WORK, POWER AND ENERGY (NUMERICAL)

1) A pump is used to lift 500 kg of water from a depth of 80m in 10s. Find

a) the work done by the pump.

b) The power rating the pump if its efficiency is 40%. (g= 10m/s²).

2) A Machine raises a load of 750 N through a height of 16m in 5 seconds. Calculate the power at which the machines works.

3) The world record for weigh-lifting is held by lakshya of India. He lifted 261kg to a height of 2.3m in 4s. Find

a) the weight lifted by Lakshya 

b) the work done by him

c) the power developed by him (g= 10m/s²)

4) A book of mass 2kg is lifted from the floor to a shelf= 210cm above the floor.

a) What is the gravitational potential energy relative to the floor?

b) What is the gravitational potential energy relative to the head of a 165cm tall person. (g= 9.8 m/s²)

5)a) If a higher body and a heavier body have equal momentum, which will have more KE ?

b) If a lighter body and a heavy body have equal KE, which will have more momentum ?

6) A person mass of 85 kg swings from a tree on the end of a vine. His feet touch the ground 4m below the tree.

a) How fast is the person moving when he reaches the ground ? g=10 m/s²

b) Does your answer depend on person mass ? If yes, give reason.

c) Does your answer depend on the length of the vine ?

7) A body, when acted upon by a force of 10 kgf,  gets displaced by 0.5m. Calculate the work done by the force when displacement is:

a) in the direction of force 

b) at an angle of 60° to the force

c) normal to the force  g= 10N/kg

8) a body P has a mass of 20 kg and is moving with a velocity of 5 m/s. Another body Q has a mass of 5 kg and is moving with a velocity of 20 m/s. Find the ratio of their kinetic energy.

9) A block, whose weight is 200 N, is pulled up a slope at a constant speed by means of a constant force of 150 N, as shown in figure:

a) what is the work done by the force in moving 5m along the slope ?

b) by how much has the potential energy of B increased?

c) Account for the difference.

10) a) What is the kinetic energy of a car of 750 kg moving at 50 kmph ?

b) How much work must be done on the car to slow it from 100 kmph to 50kmph?

c) how much work must be done on the car to bring it rest?

d) the force that does the work showing the car is constant. Find the ratio of distance needed to show the car from 100 kmph to 500 kmph to the distance needed to slow it from 50 kmph to rest. State your conclusion in a sentence..

11) A burner consumes 110 kJ of energy in 55s. What is the power of the burner in kW ?

12) a body P has kinetic energy E. Another body Q, whose mass is 9 times that of the body P, also kinetic energy E. Calculate the ratio of the velocity of P and Q.

13) A body of mass 20 kg is moving with the velocity of 1 m/s, another body B mass 1 kg is moving with a velocity of 20m/s. Find the ratio of kinetic energy of A and B.

14) A bag of wheat weighs 200 kg. To what height should it be raised to so that its potential energy may be 9800 joules? g= 9.8m/s²

15) a body mass 60 kg has the momentum 3000 kg m/s. Calculate the kinetic energy and speed of the body.

16) A bullet of mass 0.05 kg strikes a wooden target 0.2m thick, with a velocity of 300m/s, and emerges out with a velocity of 100 m/s. Calculate 

a) the loss in KE

b) the average force of friction of wood.

17) A truck weighing 1000 kg changes its speed from 36 kmph to 72 kmph in 2 minutes. Find the work done by the engine and its power.

18) A horse and dog are running with the same speed. What is the ratio of their kinetic energies if the mass of the horse is 10 times that of the dog ?

19) A cyclist along with the machines weighs 80 kg. Starting from rest , he picks up a velocity of 15m/s over a distance of 30m. Calculate 

a) the work done by the cyclist.

b) the power developed by the cyclist in 4 seconds.

20) The work done by the heart for each beat is 1 joule . Calculate the power of the heart if it beats 72 times in a minute.

21) What is the power of a pump which takes 10 seconds to lift 100 kg of water to a water tank situated at a height of 20 m ? take g= 10m/a.

22) A man of mass of 6 kg runs up a flight of 30 steps in 15 seconds . If each step is 20cm high, calculate the power developed by the man. g= 10m/s²

23) a block of mass 30 kg is pulled up a slope with a constant speed by applying a force of 200 N parallel to the slope. A and B are initial and final position of the block.

a) Calculate the work done by the force in moving the block from A to B .

b) calculate the potential energy by the block.

24) a) How fast should a man 60 kg runs so that his kinetic energyis  750 J?

b) a body of mass 1 kgs thrown vertically up with an initial speed of 5 m/s. What is the magnitude and direction of the force due to gravity acting on the body when it is at its highest point ?

25) A bullet of mass 50g is moving with a velocity of 500 m/s, it penetrates 10cm into a still target and comes to rest .

a) calculate the kinetic energy possessed by the bullet.

b) the average retarding force offered by the target.

26)  A body of mass 1 kg falls from a height of 5 m. How much energy does it possess at any instant ? take g= 9.8 m/s² ?

27) An engine can pump 30,000 litres of water to a vertical height of 45m in 10 minutes. Calculate the work done by the machine and its power. g= 9.8 m/s²

(density of the water =103 kg/m³, 1000 litre = 1m³)

28) A machine raises a load of 750 N through a height of 16m in 5 seconds . Calculate the power at which the machine works .

29) If the power of a motor is 40 kW, at what speed can it raise a load of 20000 N ?

30) Two balls of mass ratio 1:2 are dropped from the same height.

a)  State the ratio between their velocity when they strike the ground.

b) The ratio of the forces acting on them during motion.

31) A ball of mass 0.20 kg is thrown vertically upwards with an initial velocity of 20m/s. Calculate the maximum potential energy it gains as it goes up.

32) The work done by the heart is 1 joule per beat. Calculate the power of the heart if it beats 72 times in 1 minute.

 

PERIODIC TABLE AND ITS PROPERTIES (2)

Periodic Table: A tabular chart representing systematic arrangement of elements in groups and periods, in the order of their increasing atomic numbers is called periodic table.

Modern Periodic Law:  The physical and the chemical properties of all elements are the periodic function of their atomic numbers.

Periodicity of Elements: The phenomena due to which elements repeat their properties at regular intervals in a periodic table is called periodicity of elements.

Group:  The arrangement of elements in the vertical columns of the periodic table, such that all the elements in it have similar but graded chemical properties is called group.

Period: The arrangement of elements in the horizontal row in the order of their increasing atomic numbers , such that the properties of elements gradually changes from metallic to non-metallic is called period.

Periodic properties: Metallic and non-metallic character, atomic size, ionization potential, electron affinity , and electronegativity are called periodic properties.

Main points of long form of (Modern) Periodic Table):

i) There are 7 horizontal rows, called periods.

ii) There are 18 vertical columns called groups.

iii) The elements occuping left and right wings of vertical column are called normals or representative elements.

iv) The strongly metallic occupy groups I (1A) and 2(IIA) on the extreme left of the periodic table.

v) The strongly non-metallic elements are placed in groups 16(VIA) and 17(VIIA) on the right hand side of periodic table.

vi) The transition elements are accomodate in the middle of the periodic table in 3 rows. They belong to groups 3(IIB) to 12(IIB).

vii) Noble gases (rare gases) are placed in the zero group at the end of the periodic table.

viii) The rare earths (lanthanides) and radioactive elements are kept outside the periodic table to mark their peculiar properties.

Ionization Energy: The energy required to remove one electron from an isolated gaseous atom, theerrby converting it into positively charged ion is called ionization energy or ionization potential.

Electronegativity: The property of an atom to attract electrons to itself , when combined to form a compound is called electronegativity.

Electron affinity: The amount of energy released by an isolated gaseous atom of an element in its lowest state of energy, by accepting on electron to form an ion is called electron affinity.

Characteristics of a group while moving down in a group from top to bottom:

i) The number of electron shells increases by one at each step, such that total number of electron shells in each element represents the period to which the element belongs. For example, if there are three electron shells around the nucleus of an element X , then X belongs to the third period of the periodic table.

ii) The number of valence electrons (electrons in the outermost shell) of each element in a group remains the same.

iii) All the elements in a group have the same valency. The valency is equal to the number of electrons in the valency shell, when compared with oxygen . However, if the valency is compared with hydrogen, then valency is equal to the number of valence electrons for a groups 1(IA) to 13(III A). For the elements of group 14(IVA) to group 17(VIIA) the valency with respect to hydrogen is (valence electrons  - 8) and is negative. The valency of zero group element is zero.

iv) The atomic radius increases as one moves down in a group.

v) The nuclear charge(no. of protons) increases as one moves down a group.

vi) a) The metallic character of the elements from 1(IA) to group 13(III A) increases as one moves down a group.

   b) The non metallic character of non metallic elements in group 14(IV A) to 17(VIIA), gradually decreases as one moves down the group.

  

vii) a) The chemical reactivity of elements in groups 1(IA) to 13(III A) increases as one moves down a group.

    b) The chemical reactivity of elements in group 14(IVA) to 17(VIIA) decreases as one moves down a group.

viii)a) The melting points of elements in groups 1(IA) to 13(III A) decrease as one moves down a group.

   b) The melting points of elements in groups 14(IVA) to 17(VIIA) increase as one moves down a group.

ix) The ionization potential decreases as one move down a group.

x) The electronegativity decreases as one moves down a group.

xi) The electron affinity decreases as one moves down a group.

Characteristics of Periods in the Modern Periodic Table :

a) First period: It has only two elements (hydrogen and helium). It is called very short period.

b) Second and third periods: Both of these periods consists of 8 elements. They are called short periods.

c) Fourth and fifth periods: Both of these periods consists of 18 elements. They are called long periods.

d) Sixth period: It consists of 32 elements. It is called very long period.

e) Seventh period: It is an incomplete period which should have 32 elements. However, so far it has 26 elements. It is also called very long period.

While moving from left to right in a period:

a)  The number of electron shells around the nucleus remain the same.

b) The number of electron shells corresponds to the number of period to which the elements belongs.

c) The number of valence electrons increases from 1 to 8 (except in the first group where maximum number of electrons are 2).

d) The valency of an element with respect to oxygen corresponds to the number of electrons in the valence shell. When the valence electrons are 8 (or 2 in the case of helium ), the valency is considered as zero.

e) The atomic size gradually decreases.

f) The nuclear charge gradually increases.

g) The characteristics of an element changes from metallic to non metallic, till at the end of the period, the element is a noble gas.

h) The ionization potential gradually increases.

i) The electron affinity gradually increases.

j) The electronegativity gradually increase.

A) Choose the correct answer from the given options.

1) In the long form of periodic table the alkaline earth metals are placed in:

a) group 17 b) group 18 c) group 2 d)  group 1

2) Which one is a metalloid ?

a) aluminium b) silicon c) sulphur d) carbon 

3) On the basis of electron configuration of valence shell, which one is odd.

a) argon  b) krypton c) helium d) neon

4) Which one is in a solid state at room temperature ?

a) Iodine b) bromine c) fluorine d) chlorine

5) Ionization potential increases over a period from left to right, because:

a) atomic radius increases and nuclear charge increases

b) atomic radius decreases and nuclear charge decreases

c) atomic radius increases and nuclear charge decreases

d) atomic radius decreases and nuclear charge increases 

6) An element E belongs to period 3 and group 2 will have:

a) three shells in two valence electrons

b) two shells and three valence electrons

c) 3 shells and three valence electrons

d) 2 shells and two valence electrons 

7) The term used, when an isolated atom is a gaseous state accepts an electron to form an anion with release of energy is:

a) electron affinity b) ionization potential c) electronegativity d) none

8) An element P has Atomic number 16. The period and group to which P belongs is:

a) period 3 group 6  b) period 3 and group 16 c) period and group 2 d) period 6 and group 16 

9) The element P in above is :

a) metal  b) metalloid c) non metal  d) inert gas 

10) As one moves from left to right in a Periodic Table the character of elements change:

a) non-metallic to metallic b) metallic to nonmetallic c) does not change d) none

11) Which one is a metalloid ?

a) silicon b) carbon  c) sulphur d) Phosphorus 

12) The properties of the elements are periodic function of their:

a) relative atomic mass  b) mass number c) atomic number d) both a and b

13) Moving across the period of a periodic table, the elements show increasing:

a) Metallic character b) non metallic character c) electronegativity d) both b and c 

14) Compared to an element on the top of group, the element at the bottom of group shows more:

a) Metallic character b) non-metallic character c) atomic volume d) both a and c 

15) The similarities in the properties of a group of elements is because they have:

a) same electron configuration  b) same number of electrons in valence shell c) same atomic number d)  both in a and c 

16) Potassium is the element below sodium in the long form of Periodic Table. The electronegativity of potassium will be:

a) lower than sodium b) higher than sodium c) same as sodium d) none 

17) Chlorine is the element, below fluorine in the long form of periodic table. The electronegativity of chlorine will be:

a) more than fluorine b) less than fluorine c) same as fluorine d) none

18) Sodium and chlorine are in the same period. The atomic volume of chlorine will be:

a) more than sodium b) less than sodium c) same as sodium d) none

19) An element with atomic number 10 belongs to noble gas family. The family to which element with atomic number 9 belong is:

a) alkali metals b) alkaline earth metals c) halogen  d) none 

20) Amongst the halogens in group 17, the strongest oxidizing agent is :

a) iodine  b) fluorine c) bromine d) chlorine 

21) Amongst chlorine, fluorine, iodine and bromine, the least reactive is:

a) chlorine b) iodine  c) bromine d) fluorine 

22) While moving across a period from left to right, the valence electrons gradually :

a) increase b) decrease c) remain same  d) none

23) The element.s which are in liquid state about 30°C are:

a) gallium  b) Mercury  c) bromine  d) all of these

24) The metal which is most powerful reducing agent in a group I metals is:

a) potassium b) rubidium c) sodium d) lithium 

25) While moving down in group I the reactivity of elements gradually:

a) increases b) decreases c) remain same  d) none 

26) The energy required to remove the first electron from the valence shell of an isolated gaseous atom is called:

a) ionization energy b) electron affinity c) ionization potential d) both a and c 

27) The largest atomic volume amongst the following is:

a) potassium b) magnesium c) calcium d) sodium

28)  The non metals are generally electron acceptors and are good:

a) oxidizing agents b) reducing agents c) catalytic agents d) none

29) Electron affinity is maximum in:

a) alkali metals b) alkaline earth metals c) halogen d) inert gases 

30) The energy required to remove an electron from the valence shell of a neutral gaseous atom is called:

a) electron affinity b) electronegativity c) ionization potential d) none

31) Elements belonging the same group have similar properties , because:

a) their atomic number increases as one moves down the group.

b) they are either all metallic or nonmetallic elements.

c) they have similar electron configuration in the valence shell .

d) their number of electrons increases steadily 

32) With the increase in atomic number in a period

a) the metallic characters increases b) the metallic character decreases c) the chemical reactivity decreases d) the chemical reactivity increases 

33) While moving across period 2 of the periodic table, from the left to right p, the ionization potential gradually:

a) decreases  b) first decreases, then increases c) increases d) none

34) While growing down the group 16 of the long form of periodic table, the electron affinity :

a) decreases b) hardly changes c) increases d)  none

35) Which of metals in the given above will have largest atomic volume ?

a) Ca b) Ba c) Sr d) Mg

36) Metals are generally :

a) oxidizing agents b) reducing agents  c) catalytic agents d) none

37) Amongst Li, Be, C and F, the least atomic size is of:

a) Li b) C c) F d) Be

38) Amongst F, Cl, Br, I the least ionization potential is of:

a) I b) Cl c) Br d) F

39) Amongst Cl, Br, I and F, the element which has highest electron affinity is:

a) I b) Cl c) Br d) F

B) Name the following with reference to the elements of the Modern Periodic Table .

a) An alkali metal in periodic 2.

b) A halogen in period 3.

c) A noble gas having duplet arrangement of electrons.

d) A noble gas having electronic configuration 2, 8.

e) Valency of elements in group I .

f) The number of electron shells in elements of period 3.

g) The metals present in the period 3.

h) The non metals present in period 2.

i) The group of elements having zero valency.

j) A nonmetal in period 3, having valency 1.

k) Formula for hydride of a halogen in period 3.

l) Formula of sulphite of an element present in group 1, period 3.

m) Formula of hydroxide of element having electronic configuration 2, 8, 2.

n) The element in period-3, which does not form an oxide.

o) An element with least atomic size amongst carbon, nitrogen, boron and beryllium 

p) The element from elements Li, Na and K having maximum number of electron shells .

q) The elements from elements C, O, N and F having maximum nuclear charge.

r) The element from element Be, Mg, Ca, having lowest nuclear charge.

s) The element from elements fluorine and neon, having higher electron affinity.

t) Period and group of an element X, having electronic configuration 2, 8, 8, 2.

u) The most electronegative element amongst period three elements.

v) The element which has the largest atomic size amongst elements of group 1, 2 and 13.

w) The element, amongst Li, Na, K, which has maximum metallic character.

x)  The elements with maximum non metallic characters from the elements period-2.

y) The most non-metallic element from elements S, P, Cl and Ar.

z) The element with the highest ionization potential from the elements of period 1,2 and 3.

C) Complete the following by choosing the correct answers from the bracket.

a) The chemical properties of an element is the periodic function of its___.  (mass number/atomic number)

b) The serial number of an element in a Periodic Table is also its____. (mass number/ atomic number)

c) The number of electrons in the valence shell of an element represents its ____. (period/group)

d) The number of electrons shells around the nucleus of an atom represents its ____. (period/group)

e) The strongly active_____(metals/non-metals) are placed in group I A and II A.

f) The ____(metals/nonmetals) are placed on the right hand side of the Periodic Table.

g) The elements placed in the extreme right hand side group are called _____. (noble gases/light gases)

h) The elements occupying the right and left wing vertical columns are called ____(Normal/ transition ) elements.

i) The ______(normal.transition) elements are accommodate in the middle of the periodic table.

j) Hydrogen is a non metal which is placed at the head of a group of most active____. (Non-metal /metals)

C) Match the Columns 

    Column A                           Column B

i) period 4 group II A         a) Argon 

ii) period 2,  group III A     b) calcium 

iii) period 3 group zero     c) boron 

iv) period 2, group VIA      d) silicon 

v) period 3, group IVA       e) oxygen 

D) 2 MARKS QUESTIONS 

1a) Name three alkali metals and state their group number.

b)  Name three alkaline earth metals and state the group number.

c) Name three halogens and state their group number.

d) Name three noble gases and state their group.

 

2)a) What do you understand by the term 'Transition elements' ?

b) Select the transition elements from the following list:

List: potassium, calcium, manganese, chromium, copper, calcium, iron, platinum.

3) An element has atomic number 19. Where would you expect this element in the Periodic Table and why ?

4)a) How does the atomic radius change in a period ?

b)  element         P          Q          R

At.radius         1.86A° 2.31A° 1.52A°

 Arrange the elements in the table above, such that the least metallic element comes first and the most metallic element comes last.

5) Amongst the elements P(at.no 14), Q(at.no 6) and R(at.no 15), which elements have similar chemical properties and why ?

3 Marks Questions 

1) An element with atomic number 18 is a noble gas. Into which families will you place elements with atomic number 17 and 19 and why ?

2)a) i) Which period in the Periodic Table is the shortest ?

ii) Name all the elements present in the period.

b) i) Which Period in the Periodic Table is the longest and complete ?

ii) How many elements are present in it?

3) Metallic properties of the elements change to non-metallic properties as one move from left to right in a periodic of the periodic table. explain ?

4) The bigger the atomic volume, more metallic is an element. Explain the statement.

5) i) What do you understand by the term electronegativity ?

ii) Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K and Ca.

Amongst the list of elements given above pick out.

    a) most electropositive element 

    b) most electronegative element

    c) noble gas 

6) Why do the halogen atoms have a very strong electron affinity? Explain .

7) i) What do you understand by the term electron affinity ?

ii) Does electron affinity represent energy released or absorbed ?

iii) Name an element having strong electron affinity .

iv) arrange Br, F, I and Cl in the order of increasing electron affinity.

8) Explain why reducing power of elements increases as one goes down a group.

9) Explain why the reducing power of the elements decreases as one moves from left to right in a period ?

10) Why the elements lying on the extreme left hand side group, are very active metals ?

11) Why are the elements lying in a group prior to zero group of the Periodic Table very strong and nonmetals ?

12a) i) Name one most metallic elements in the Periodic Table.

ii) Name one most non metallic element in the Periodic Table.

b) How does electronegativity vary (i) in a period (ii) in a group

13)a) How does ionization potential vary 

i) in a period

ii) in a group

b) Table below shows a part of the Periodic Table . State what happens as one moves from left to right to 

i) metallic character 

ii) atomic radius of elements.

Li      Be      B    C     N     O      F 

Na    Mg    Al   Si     P      S     Cl 

14) The atom of sodium (at.no 11) is bigger than the atom of chlorine (at. no. 17). Why ?

15) State two merits and two demerits of the long form of the Periodic Table .

5 Marks Questions 

1) Use the letters only in the Periodic Table given below to answer the questions that follow:

a) State the number of valence electrons in atom J.

b) Which element shown forms ions with a single negative charge ?

c) Which metallic element is more reactive than R?

d) Which element has its electrons in four shells?

e) Which element has the smallest atomic size ?

2) An element E has atomic number 17. Answer the following questions regarding E:

a) Name the group of E in the long form of periodic table.

b) Name the period of E in the long form a Periodic Table.

c) Is the element E metal or nonmetal ?

d) Name the element E on reacting with burning magnesium will form a compound. Name the formula of the compound.

e) Name the compound formed in (iv) above.

3) An element E has atomic number 14. Answer the following questions .

a) Name the period E belongs to.

b) Write the number of electron shells in E.

c) Write the number of electrons in the valence shell of E.

d) Name the group of element E.

e) Name the element E is.

4) The table given below shows long form of Periodic table. In the table alphabet letters are used rather than symbol of an elements . Answer the following questions :

a) Name the number of valence electrons in K.

b) Name the element which forms a negative divalent ion.

c) Name the metallic element more reactive than F.

d) Name the element in which electrons are arranged in 5 shells.

e) Name the kind of chemical bond formed between J and L.

5) An atom A (atomic number 11) and an atom B(atomic number 17) belong to 3rd period of long form of periodic table.

a) Name the atom/s which is/are more metallic among A and B.

b) The (A) and (B) belong to the which families of elements ?

c) Name the type bond formed between A and B is.

d) State the solubility of the compound A and B.

e) What is position of A and B in long form of periodic table ?

6) Amongst E, F, G and H elements, of atomic 4, 9, 15 and 16 respectively.

a) Name the element of the group 17.

b) In the given above the elements which has the three electron shells ?

c) In the given above name the element with highest electronegativity.

d) In the given above which is metal ?

e) In the given above which element is a non metal?

WORK, POWER AND ENERGY

1) Complete the following statements by choosing word/words from the box.

(maximum, power, energy, watt, 746, positive, joule , Kinetic, displacement 1N, force, 0.746 1m, mechanical energy, work)

a) Work is measured as a product of____ and_____.

b) One fuel work is said to be done when a force of___ displaces a body by___.

c) The SI unit of work is____.

d) If the force and displacement are parallel to each other, the work done is___ and___ .

e) Kilowatt-hour is the unit of____ .

f) The SI unit of power is___ .

g) Horsepower is the unit of ____ .

h) The energy of a body due to its motion is called___ energy.

i) 1 horsepower = ____W = _____ kW.

j) The CGS unit of energy is____ .

k) The sum potential and kinetic energy of a body is called its____ .

2) Complete the following statement by choosing the word/words from those given in the brackets:

 

a) In a circular path, the work done by a body is____ (zero/ not zero)

b) Power is a____(scalar/vector) quantity.

c) If the mass of a body is doubled, its kinetic energy gets ____(doubled/4 times)

d) The bob of a simple pendulum has maximum____(Kinetic/ potential) energy when it is at its extreme position and has maximum___(kinetic/potential) energy in its mean position.

3) State the True or False . Also correct the false statements.

a) If the displacement is normal to the direction of the force, the work done is negative.

    

b) When a body is released from a height, the kinetic energy of the body is gradually changed into potential energy.

 

c)  When a body is thrown upwards , the potential energy of the body is gradually transformed into kinetic energy.

d) The change of one form of energy into another form is known as conservation of energy.

4) The following questions are related with an oscillating pendulum, oscillating on either side of its rest position. State whether the following questions of True or False :

a) It has the maximum kinetic energy at its extreme position.    

b) it has the maximum potential energy at its rest position.      

c) The pendulum has only kinetic energy.     

d) The sum of its kinetic energy and potential energy remains constant throughout the motion.    

5) Very Short Questions:

1) What are the conditions under which no work is done by a force acting on a body ?

2) Is work a scalar or vector quantity ?

3) In which case the work done by a force will be maximum:

When the angle between the direction of force and the direction of motion is 90° or 0°?

4) State a angle of a situation where the work done by a force is negative.

5) Give an example when a work done by a force acting on a body zero even though the body gets displaced from its initial position by the application of force.

6) For maximum work what should be the angle between the force in the displacement ?

7) State the SI unit of the energy?

8) Name any two units of the energy other than SI unit.

9) State the angle between the direction of force and the direction of motion of a body so that the work done is 0.

10) Name the physical quantity whose unit is watt.

11) Define the term watt.

12) Difference between work and power.

13) Name the various sources of energy.

14) Is it possible that no transformation of energy takes place even when a force is applied to the body ?

   

15) A light mass and a heavy mass have equal momentum. Which are have more kinetic energy ?

16) A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy as its velocity becomes zero ?

  

17) On what factor does the kinetic energy of a body depend ?

18) What happens to the kinetic energy of a body when the:

a) mass of the body is double at constant velocity.    

b) velocity of the body is doubled at constant mass ?

c) mass of the body is doubled but the velocity is reduced to half ?

19) When a stone is thrown a vertically upwards, its velocity goes and decreasing. What happens to its potential energy as its velocity becomes zero ?

20) What kind of energy is possessed by the following:

a) a flying aeroplane: 

b) a ceiling fan in the office spring: 

c) a compressed spring : 

d) A streched rubber band: 

e) a man climbing a hill : 

f) A running car: 

21) While the following are in use, State the energy changes:

a) A the steam engine: 

b) A loud speaker : 

c) burning coal :

d) A solar cell : 

e) petrol or diesel engine automobile : 

f) A washing machine: 

22) A cell convert one form of energy into another. Name the two forms.

23) What kind of energy transformation takes place at a hydroelectric power station ?

    

24) What kind of energy transformation take place at a thermal power station ?

    

25) State the energy changes that takes place when a car at rest starts, accelerates and stopes on the application of breaks.

26) What is the SI unit of work ?

27) How much is the work done by a body when it moves over a complete circular path ? Give reason for your answer.

28) Name the physical quantities for which the following are used as units.

a) kilowatt  b)  kilowatt-hour 

29) A truck driver starts off with his loaded track. What are the major energy changes that take place in setting the truck into motion ?

  

30) State the energy changes in an oscillating pendulum.

      

31) Express 1 kWh in terms of SI unit of energy.

     

32) Which physical quantity does the electron volt measure ? How is it related to the SI unit of this quantity ?

33) What should the angle between force and displacement be to get the:

a) minimum work ?     

b) maximum work ?    

34) Name the chief energy transformation that occurs:

a) in a lot speaker :    

b) in an electric cell (primary): 

6) Short Questions:

1) In which of the following cases, is the work being done ?

a) a man pushing a wall 

b) A coolie standing with a load of 12kg on his head.

c) a boy climbing a staircase.

d) a boy carrying a box on his head and moving on a frictionless horizontal surface.

       

2) The sign of the work done by a force on a body is important to understand. State carefully if the following quantities are positive or negative:

a) work done by a man in lifting a bucket out of well by means of rope tied to the bucket.

b) Work done by gravitational force in the above case.

c) Work done by friction on a body sliding down an inclined plane.

d) Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity.

e) Work done by resistivity force of air on a vibrating pendulum in bringing it to a rest.

3) a) Define the term power.

b) How is power related to force and velocity ?

c) What do you understand by the term 'horsepower'? Express it in SI system.

4) What is meant by energy? State its unit. How is energy related to power?

5) Give one relevant example for each of the following transformation of energy :

a) kinetic energy to potential energy.

b) mechanical energy to heat energy 

c) mechanical energy to electrical energy

d) electrical energy to heat energy and then to light energy.

e) chemical energy to electrical energy 

f) sound energy to electrical energy

g) electrical energy to mechanical energy.

6)a) Define one watt and 1 kWh.

b) converts ¹ kWh into joule.

7) Write an expression for the work done by a constant for acting on a body which gets displaced from its initial position in a direction different from the direction of the force.

b) Give an example when work done by a force acting on a body is zero even though the body gets displaced from its initial position by the application of force.

8) State the principle of conservation of energy.

OR

State the law of conservation of energy.

9) Define 

a) i) work ii) power iii) energy 

b) How is work done related to the applied force?

c) By what factor does the kinetic energy of a moving body change when its speed is reduced to half ?

d) From the ground floor, a man comes up to the fourth floor of a building using the staircase. Another person comes up to the same floor using an elevator. Neglecting friction, compare the work done in the two cases.

7) Multiple Choice Questions 

1) When work is done on a body:

a) it gains energy b) it loses energy c) its remains constant d) none

2) A man pushes a wall but fails to displace it. He does:

a) negative work b) positive work c) no work d) maximum positive work 

3) The work done by a force on a body will be positive if the:

a) a body does not a move b) body moves perpendicular to the direction of the applied force c) body moves along the direction of the applied force d) body moves opposite to the direction of the applied force.

4) The power of a body which is doing work at the rate of 1 joule per second is:

a) 10W b) 1W c) 2W d) 5W

5) Power is:

a) the energy needed to move an object b) force x distance  c) work x acceleration d) the rate of doing work

6) The SI unit(watt) of a power is equivalent to :

a) kgm/s² b) kg m²/s² c) kg m²/s d) none

7) If a force is applied on a body and it moves with a velocity c, the power will be:

a) F x v b) F/v c) F/v² d) F x v²

8) a calibrated spring balance will be used anywhere in the universe to correctly measure:

a) weight in N b) weight in kg c) mass in N d) mass in g.

9) When a body falls freely:

a) its P. E is converted into K. E

b) its K. E is converted into P. E

c) its mechanical energy is converted into heat energy. d) none

10) A body at rest may possess :

a) kinetic energy b) potential energy c) momentum d) none

11) When the speed of a moving object is doubled, its :

a) accelerations is doubled b) weight is doubled  c) kinetic energy is doubled  d) kinetic energy increases 4 times.

12) The unit of energy is:

a) newton b) watt c) metre/second d) joule 

13) When a body is projected in a gravitational field:

a) its K. E increases b) its P. E increases c) its total energy increases d) its Total energy remains same

14) kinetic energy of an object is proportional to:

a) its velocity  b) its weight c) its momentum  d) the square of its velocity 

15) An electrical motor lifts a 8 kg box vertically through 2.5 m in 10 second. The power produced by the motor is :

a) 0.32W b) 3.2W c) 3.0W d) 20W

16) A pendulum is oscillating on either side of its rest position. Pick out the correct statement:

a) it has only kinetic energy.

b) It has the maximum kinetic energy at its extreme position

c) it has the maximum potential energy at its rest position 

d) The sum of its kinetic and potential energy remains constant throughout the motion.

17) If the mass of a body is halved and its velocity is doubled , the kinetic energy of the body:

a) gets doubled  b) gets 4 times c) gets 8 times d) remains unchanged 

18) a car is running at a speed of 15 kmph while another similar car is moving at a speed of 30 kmph . Their kinetic energies are in the ratio of 

a) 1:2 b) 2:1 c) 1:4 d) 4 :1

19) Two bodies with kinetic energy is in the ratio of 4:1 are moving with equal linear momentum. The ratio of their masses is :

a) 1:2 b) 1:1 c) 4:1 d) 1:4

20) A 1 kg mass has a kinetic energy of 1 J when its speed is :

a) 0.45m/s b) 1m/s c) 1.4m/s d) 4.4 m/s

21) The power of a moving body is stored in the form of :

a) work and time b) force and distance c) force and velocity  d) distance and acceleration

REFRACTION OF LIGHT (NUMERICAL)

Bangalore preparation glass block of refractive index 1.5 calculate the angle of incidence the refractive index of water with respect to air is 43 what is the refractive index of air with respect to water the speed of the light in air is 300 10 calculate the suitable lighting refractive index of class is 1.5 a small air bubble in the interior peace of glass plate appears to be an observer looking normally down into the class to be 2.0 from the nearest surface what is the actual distance what is critical angle for class given applied stag the surface of a transparent medium angle A presidency refractive into medium at an angle of refraction 45 what is the refractive index of the mediumThe the coin lies in the bottom of the truck in which height of a water 4315 and how much it sinceres from the bottom calculus federal light in water giving suitable lighting at 10 and refractive and reserve water 43 the velocity of the light in diamond 121 what is the refractive index velocity of the light in AR 300 10 a post is time appear raised by 7.0 when placed under triangular 1.5 find the thickness of the class block of refractive index

REFRACTION OF LIGHT THROUGH A PLANE SURFACE AND PRISM

What is the refraction is it necessary that the way of life must change its path during refraction draw a diagram showing a Ray applied going from here to water mark the following incident ray reflected the angle of incidence angle of refraction normal to refracting surface Ray of light is in normally on the surface of a glass lab complaint the diagram and determine the value of the following angle of incidence angle of refraction figure show the way of light going from medium state the law of refraction which of the following diagram represent the correct refraction through a glass slap how do you define refractive index of a medium how do you define absolute refractive index of media how do you Express refractive index of medium in terms of in terms velocity of light in terms of absolute refractive index figure shows a bottom surface of a glass black silver to act as a mirror which one of the following diagram best represent the part of a light way that enter the block through the top service and observer looking figure which one of the position a b c d is the nearest to the real position of lights refraction the correct addressless than 1 absolute refractive in disease of glass and water 32 and 43 calculate repractive index of glass with respect to water refractive index of water with respect to class write the formula so the relationship from real depth and apprentice available for deep with the refractive index of water is 43 what is actual date refractive index 32 and 43 respectively calculate the velocity of light in glass and water velocity of light in vacuum glass water soon in the figure calculate the refractive index state the principle of reversibility prove that the refractive index of water related to each other by the listray diagram showing refraction through a glass slab what is mean by the refractive index of a class in 1.5 write the formula used to find the refractive index of glass area applied passes from air into the liquid the angle of incident is 25 while the angle of refraction if 15 calculate the refractive index of the liquid area of light passes through rectangular glass block as soon draw the normal to surface of the point of incidence find the angle of incidence find the angle of refraction and calculate the refractive index of the block complete the diagram to show the emergency from the block what is the relationship between the depth and April 43refractive index of water is 43 fraction through a glass Slam which of the represent the refracted while studying a refraction through a glass number of observation taken from angle of incidence and angles of refraction so the graph related with this experiment which quantities are taken along the two accessories why a pencil is divine to water how does it appear from outside draw the diagram if his full line situated the bottom of the river give reason for the same draw the red diagram showing this what are the following in terms of A B and C realty how are the real captain apparent related with each other draw the diagram of prism in the mark the following refracting face refracting angle refractive draw the course of a monochromatic Ray underground refraction through a prism and mark the following angle of incidence angle of refraction angle of deviation angle of prism what is the relation by which angle of incidence and angle of emergence in case of a prism related to each other minimum the beast write the relation for refractive index of the material of the President of the angle of prism one of the refracting process of prism complete the diagram showing the various angle for refraction through the prism what is the relation between what is the value of in terms the angle of prism and angle of minimum what is the value of angle of refraction terms of angle of prism what is the angle which refracted inside the prism is make the base of the prism which of the two colours what is the angle between the incidental the emergent ray draw the course of the year of through genetic by binocular indicating really tabs inversion involved explain the following refractive index of every material is always less than 1 array incidently normally on the surface of water goes undergrated discussion mathematically thinking up starts Sun becomes visible a little time before actually comes horizon some remains what is total internal reflection how to define critical angle how is criticalarea of light when going from dancer to rare medium is instance on importance of the critical angle what is angle of attraction in the rare medium describe the continent experimental the help of a diagram a coin C place of the bottle of a class containing water appeals to the suspended in air at C explain and draw the ray diagram the person ab of the tube to be glittering an observed from outside explain and draw the ray diagram Ray applied ab travelling from blast is incidently at an angle of 60 raise the path of it emergence out of glass critical angle for class 2 year is 42 explain the concept the inferior in erase with the help of a diagram explain the concept of Neeraj will the help of the rare diagramfill in the blanks refractive index of water is applied goes from more than some medium the angle of refraction is the entangle of incidence the bottom the water pond appears to be when observed from outside refractive index of a median is to ratio between depth to the depth total internal reflection is observed when the if the light of Ghost from two medium greater the refractive index and medium is the value of the critical angle state whether the following statement as a result of refraction area of light muschanges path in case of relighted goes from water to air angle of refraction is greater than angle of incidence in case area applied goes from here to glass angle of refraction a smaller than angle of incidence refractive index of air with respect to classes less than 1 for a reincidence from tension medium Maine aap total internal reflection takes place of the light goes from the arre to density

ACID, BASE, SALT

A) Choose the correct alternative 

1) Which is a hydroscopic substances 

a) conc. sulphuric acid  b) Calcium oxide c) Phosphorus pentoxide d) all of these 

2) The degree of ionization of an acid is called:

a) strength of an acid  b) concentration of an acid c) combining capacity of an acid d) both a and b

3) The property of salts, giving up water of crystallization to the atmosphere is

a) Deliquescences b) hybroscopic c) efflorescence d) none

4) The property of salts of absorbing moisture from the air and then changing to liquid state is:

a) Deliquescences b) hybroscopic c) efflorescence d) none

5) The property of salts of observing moisture from air, but do not change into liquid state is:

a) Deliquescences b) hybroscopic c) efflorescences d) none

6) A salt which is amphoteric in nature is:

a) ZnO b) CuO c) Fe₂O₃ d) CaO

7) Which of the following forms acidic solution in water ?

a) CuSO₄ b) ZnSO₄ c) K₂SO₄  d) both a and b 

8) Ammonium hydroxide solution is:

a) alkaline in nature b) acidic in nature c) neutral in nature d) none

9) Ammonium sulphate solution is:

a) alkaline in nature  b) acidic in nature c) neutral in nature d) none

10) Sodium carbonate solution is:

a) alkaline in nature  b) acidic in nature c) neutral in nature d) none

11) Sodium sulphate solution is:

a) alkaline in nature b) acidic in nature c) neutral in nature d) none of these 

12) Copper sulphate solution is:

a) alkaline in nature b) acidic in nature c) neutral in nature d) none of these 

13) An oxide of a nonmetal used for making soft drinks is:

a) SO₂ gas b) CO gas c) NO₂ gas d) CO₂ gas

14) A soluble metallic compound with H⁺(aq) ions of an acid to form a salt in water as only products is:

a) alkali b) base c) basic salt  d) none of these 

15) An acid salt is:

a) Potassium hydrogen sulphate b) potassium hydrogen carbonate c) magnesium hydrogen carbonate d) all of these 

16) an inorganic acid amongst the following is:

a) Acetic Acid b) formic acid c) hydro-cyanic acid d) oxalic acid

17) A tribasic acid is:

a) H₂SO₃ b) H₃PO₄ c) HNO₃ d) CH₃COOH

18) The salt which forms neutral solution in water is:

a) sodium sulphate b) ammonium chloride c) copper sulphate d) silver nitrate

19) a salt which forms an acidic solution in water is:

a) sodium chloride b) ammonia carbonate c) silver nitrate d) potassium sulphate 

20) A salt which forms basic solution in water.

a) CH₃COONH₄ b) CH₃COOK c) KCl d) NaNO₃

21) The base amongst the following compounds is :

a) sodium hydroxide b) potassium hydroxide c) copper hydroxide d) ammonium hydroxide 

22) 2Al(OH)₃+ 3H₂SO₄ ---> Al₂(SO₄)₃ + 6H₂O

in the above chemical equation the acidity of Al(OH)₃ is:

a) 1 b) 6 c) 3 d) 2

23) The salt which forms a neutral solution is water is:

a) (NH₄)₂SO₄ b) Na₂SO₄ c) Na₂CO₃ d) Cu(NO₃)₂ 

24) the colour of pH paper in odourless solution of ph7 is

a) deep blue b) yellow c) green d) Orange

25) The colour of pH paper in limewater [Ca(OH)₂] is 

a) green b) red c) blue d) Orange 

26) Ammonium hydroxide is an example of 

a) strong alkali b) weak alkali c) strong base d) none of these 

27) Sodium nitrate is an example of:

a) normal salt b) acidic salt c) basic salt d) none of these 

28) Sodium acetate(CH₃COONa) is an example of:

a) normal salt b) basic salt c) acidic salt d) none of these 

29) pH of dil. H₂SO₄ is more than acetic acid. So Sulphuric acid has

a) greater concentration of H⁺ ions b) same concentration of H⁺ ions c) low concentration of H⁺ ions d) none of these 

30) The base amongst the following hydroxides is:

a) sodium hydroxide b) ammonium hydroxide c) copper hydroxide d) potassium hydroxide

31) Zinc oxide dissolves in dilute hydrochloric acid as well as in conc. NaOH solution. The nature of zinc oxide is 

a) acidic b) alkaline c) neutral d) amphoteric 

32) The pH of a solution is 6. The pH of the solution can be increased by adding to it :

a) few drops of conc. KOH solution b) few drops of conc. HCL c) 1 ml of water d) none of these 

33) A particular solution contains molecules and ions of a solute, so it is a 

a) strong acid b) strong base c) weak acid d) sodium chloride solution 

34) An example of a complex salt is:

a) copper sulphate b) potasium hydrogen sulphate c) iron(II ) ammonium sulphate d)  tetra amine copper (II) sulphate

35) Acid is a compound, which on dissolving in water furnishes:

a) hydrogen ion b) hydroxil ion c) hydronium ion d) both a and c 

36) An aqueous solution of hydrogen sulphide gas is a :

a) strong acid b) strong alkali c) weak alkali d) weak acid

37) Conc. nitric acid stains the skin:

a) black b) brown c) yellow d) red 

38) Which is the base amongst the following ?

a) LiOH b) NaOH c) Mg(OH)₂ d) KOH

39) Which acid is the dibasic amongst the following ?

a) sulphuric acid  b) sulphurous acid c) hydrogen sulphide solution d) all of these 

40) Which is triacidic base?

a) Almunium hydroxide  b) iron(II ) hydroxide c) ammonium hydroxide d) both a and b

41) degree of ionization of an acid X is 6%. The acid X is:

a) dilute acid  b) concentrated acid c)?weak acid  d) strong acid

42) the pH of solution is 1.2. The solution is :

a) Mildly acidic b) strongly acidic c) Mildly alkaline d) strongly alkaline

43) the pH of a colourless liquid is 13. The liquid is a :

a) very strong acid b) very strong alkali c) a weak acid d) a weak alkali 

44) A solution turns pH paper blue. The pH paper is kept within the solution and another solution X is added drop by drop. It is found that pH paper turns green. The nature of solution X is:

a) Acidic b) alkaline c) neutral d) none of these 

45) The metallic oxide which dissolved in water to form alkali is :

a) K₂O b) Al₂O₃ c) ZnO d) CuO

B) Identity the following:

1) A compound which on dissolving in water furnishes hydronium ion as the only positively charged ions.

2) An acid which furnishes 3 hydronium ions per molecules on ionization.

3) An Acid which undergoes partial dissociation, on dissolving in water.

4) A water soluble base, which furnishes hydroxyl ions.

5) The number of H⁺ ions of an acid which react completely with one molecule of base to form salt and water as only products .

6) An indicator which turns pink in alkaline solution and colourless in an acid solution.

7) A hydrated salt which loses its water of crystallization on exposure to air.

8) The phenomena due to which salt reacts with water to form parent acid and alkali.

9) A salt which absorbs moisture from air and changes into liquid state.

C) Complete the following by choosing the correct answers from the brackets:

1) A more volatile acid obtained, when a less volatile acid reacts with sodium nitrate is ___.( sulphuric acid/nitric acid)

2) an example of an acid derived from a mineral acid is ____.(acetic acid/citric acid/hydrochloric acid)

3) an example of a base which is not on alkali is ____.(caustic potash/ copper hydroxide/ ammonium hydroxide)

4) an example of a weak acid is____(HCl/H₂CO₃/HNO₃/H₂SO₄)

5) an example of a weak alkali solution is____.( sodium hydroxide/ potassium hydroxide/ammonium hydroxide)

6) An acid having a basicity 2 is ____(acetic acid/nitric acid/carbonic acid)

7) An example of insoluble salt is____.(Na₂SO₄/CuSO₄/PbSO₄/ZnSO₄)

8) an example of a salt which produces neutral solution on hydrolysis is____.( sodium acetate /sodium carbonate/sodium chloride)

9) An example of acidic salt is____,(NaHSO₄/CH₃COONa/K₂SO₄)

10) The colour of hydrated copper sulphate is____.( light blue/black /white)

11) the example of an amphoteric hydroxide is ____.(Ca(OH)₂/ Cu(OH)₂/ Al(OH)₃/Fe(OH)₃)

12) the hydroxide which is soluble in excess of NaOH is____. (Al(OH)₃/ Fe(OH)₂/ Cu(OH)₂)

13) an oxide of a metal which is amphoteric in nature is ____. (PbO/Pb₃O₄/PbO₂)

D) Match the Column A and column B 

Column A.        Column B

1) Acidic salt   a) sodium Potassium carbonate 

2) mixed salt   b) Alum

3) complex salt  c) sodium carbonate 

4) double salt   d) sodium zincate 

5) normal salt   e) sodium hydroxide carbonate 

E) Write balanced equation for the following reactions

1) potassium hydrogen carbonate and dilute sulphuric acid.

2) copper oxide and dilute hydrochloric acid.

3) manganese(IV) oxide and concentrated hydrochloric acid.

4) Sulphur and hot concentrated nitric acid.

5) sodium nitrate and concentrated sulphuric acid.

F) Short questions (2)

1) Differentiate between hydracids and oxy-acids. Give examples.

2) On what basis are the strength of a) acids  b) alkalis determined ?

3) differentiate between a strong acid and weak acid. Give two examples .

4) differentiate between a strong alkali and a weak alkali.

5) Explain why is the basicity of an acetic acid is one, and the acidity of magnesium hydroxide is 2.

6) How will you obtain a) Sulphuric acid from an acidic oxide b) potassium hydroxide from a basic oxide ?

7) write fully balanced chemical equations for the reaction of conc. Sulphuric acid with a) metallic chloride b) metallic nitrate, why the chloride and nitrate form their respective acids.

8) 1 molar solution of Acetic acid is a weak acid as compared to 0.1 molar solution of hydrochloric acid? Why? Explain your answer.

9) Give one chemical property (not indicators) with a balanced equation in each which are typical of a) dilute acid b) a dilute aqueous alkalis.

10) Mention the terms defined by the following sentences:

a) A soluble base.

b) An insoluble solid formed, when two solution are mixed together.

G) 3 Marks Questions 

1) Why is sulphuric acid is a diabasic acid ? Give three reasons. Support your answer with equations, wherever possible.

2) State two chemical properties each with equations for 

a) a strong solution containing ions solution containing H⁺ (aq) ions.

b) a solution containing OH⁻ ions.

3) Show ironically why

a) phosphoric acid 

b) Sulphuric acid

c) Acetic Acid are called acids.

4) Define the following terms giving one example in each case 

a) an acid 

b) A base 

c) An acid salt.

5) Zinc metal and Aluminium metal are amphoteric in nature. What do you understand by the statement ? Support your answer by writing fully balanced chemical equations.

6) Solution A is a strong acid

    Solution B is a weak acid 

    Solution C is a strong alkali 

a) which solution contains soluble molecules in addition to water molecules ?

b) which solution will give a gelatinous white precipitate with zinc sulphate solution ? The precipitate disappears when an excess of the solution is added.

c) Which solution could be a solution of glacial Acetic Acid ?

d) Give an example of a solution which is a weak alkali.

7) What is observed when :

a) Hydrogen sulphide gas is passed through the lead acetate solution ?

b) Neutral litmus solution is added to sodium hydrogen carbonate solution ?

c) a small piece of iron is placed in copper sulphate solution ?

8) a) Acids dissolve in water to produce positively charged ions. Draw the structure of these positive ions. 

b) Explain , why carbon tetrachloride does not dissolve in water.

c) Elements Q and S react together to form an ionic compound. Under normal conditions , which physical state will the compound QS exist in .

d) can Q and S, both be metals ? justify your answer.

9) Write the observations and balanced equation for the following reaction:

a) sodium hydroxide is added drop by drop, till in excess, in a solution of zinc sulphate.

b) ammonium hydroxide is added first in small quantity and then excess to a solution of copper sulphate.

c) Excess of ammonium hydroxide is added to a substance obtained by the action of hydrochloric acid in silver nitrate.

10) Starting with copper chips and concentrated nitric acid, describe briefly how you can prepare black copper oxide.

11) For each of the conversion A, B, C, D and E in the scheme below, state briefly in words, how the conversions can be carried out.

12) Starting from potassium hydroxide and nitric acid, how will you prepare crystals of potassium nitrate ?

13) Briefly describe, how will you obtain crystal of zinc sulphate starting from zinc and dilute sulphuric acid.

14)  Give one chemical test to distinguish between the following pairs of compounds.

a) Zinc sulphate solution and zinc chloride solution.

b) iron(II ) chloride solution and iron(III ) chloride solution.

c) Calcium nitrate solution and calcium chloride solution.

15) A solution M turns blue litmus red while another solution N turns red litmus blue. In the above context answer the following questions.

a) What does M must contain?

b) What does N must contain?

c) When M and N are mixed together, name one of the product formed .

d) when M and N are mixed together, name the other products formed.

e) If a piece of magnesium was put in to a solution M, name the gas evolved.

16) The pH value of 3 solution P, Q, R are the given in the table.

Solution           pH value 

P.                       12

Q                        2

R                        7

Answer the followings:

a) Which solution will have no effect on litmus solution?

b) Which solution will liberate CO₂ when reacted with sodium carbonate?

c) Which solution will turn red litmus blue?

d) Which solution will turn blue litmus red?

e) Which solution is also known as alkali 

17) Answer the following:

a) The pH of a solution S is 10. What is nature of solution ?

b) If the pH of solution is to be the increased name the compound we should add to it.

c) Name the kind of particles present in the solution of the sodium chloride.

d) Name kind of particles present in the solution of carbonic acid.

e) Name kind of particles present in the glucose solution.

18) You are provided with copper carbonate and concentrated sulphuric acid. How will you proceed to prepare hydrated crystals of copper sulphate ?

19) You are required to prepare lead sulphate from lead carbonate. Briefly explain how will you proceed.

20) We cannot prepare calcium sulphate by treating marble chips with dilute sulphuric acid. Outline the procedure to prepare calcium sulphate from marble chips.

MOTION IN ONE DIMENSION

1) a) What is understand by the term 'distance'?

b) Is distance a scalar or a vector quantity ?

c) What is the SI unit of distance ?

2)a) What is understand by the term 'displacement'

b) Is displacement a scalar or a vector quantity ?

c) State the SI unit of displacement.

3) Differentiate between distance and displacement.

4) Give an example to illustrate the difference between distance and displacement.

5) Give an example of a motion in which the displacement is zero but the distance travelled is not zero.

6) Name the physical quantity that represents the rate of change of displacement.

7) Define the following terms:

a) speed 

b) velocity

8) Complete the following table:

Quantity    CGS unit     SI unit    scalar or vector

a) speed     ____             ____        ______

b) velocity  _____           _____       ______

9) A car moving along a straight line covers a distance of 1 km due east in 100s. Find:

a) the speed of the car.

b) the velocity of the car.

10) What is meant by 

a) uniform velocity 

b) variable velocity 

11) Give one example for each of the following:

a) uniform velocity 

b) variable velocity

12) How is the displacement related to time a body moving with uniform velocity ?

13) The velocity of a body at any stand is v m/s towards east and after a time t second , it is v m/s towards west. Find 

a) the change in velocity.

b) the rate of change of velocity.

14) Give an example of a motion in which the average velocity is zero but the average speed is not zero.

15) Give an example of a motion in which speed is constant but velocity is variable.

16) Define the following terms:

a) acceleration 

b) retardation.

17) Differentiate between acceleration and retardation.

18) State the SI unit of acceleration.

 Is acceleration a scalar or vector quantity.

 The speed of a particle is constant. Can it have a acceleration ?

 if the above answer is yes, give an example.

19) draw a diagram to show the motion of a body whose speed remains constant but the velocity changes continuously.

20) Explain the following terms and give one example of each:

a) uniform acceleration

b) uniform retardation.

21) A student takes 15 minutes to travel from his home to the school with a uniform speed of 5 kmph. What is the distance of his school from the home ?

22) A body starts from rest and acquires a velocity of 20 m/s in 2 s. Find the acceleration.

23) A car takes 3 h to reach from a station A to a station B and then 5 h to return back from the station B to the station A. The distance between the two station is 240 km. Find 

a) the total distance travelled by the car.

b) the total displacement of the car.

c) the average speed of the car.

d) the average velocity of the car.

24) A car accelerates at a constant rate of 10 km/h². What does this statement mean?

25) At a certain instant the velocity of vehicle moving in a straight line is 40 km/h. After 2s, the velocity is 46 km/h and 2s later it is 52 km/h. What is the acceleration of the vehicle in m/s²?

26) The following table gives the speed of the four bodies P, Q, R, S, moving in straight lines .

Time  speed  speed  speed  speed

            of P      of Q     of R     of S

  (s)     m/s       m/s     m/s    m/s

   0        10          10       10      10 

  10       12          10        7       15 

  20       14          10        4        6

  30       16          10        1        9

Using the information given in the table, answer the following:

a) i) Which body moves with uniform velocity ?

ii) What is its velocity ?

b) i) Which body moves uniform acceleration ?

ii) What is its acceleration ?

c) i) Which body moves with uniform retardation ?

ii) What is its retardation ?

d) What is the velocity of the body R during the 25th second ?

e) What is the type of motion of the body S ?