ICSE MODEL TEST PAPER (PHYSICS) 22/23

Model test paper 1

              SECTION - A

(All questions are compulsory)

Question 1

a) i) what is meant by the term energy? Name the two forms of mechanical energy. (2)

ii) Define critical angle. (1)

iii) Define erg. (1)

b) i) A water pump raises 373kg of water through a height of 10m in 10 seconds. Calculate the power at which the pump wirks. (Assume g= 10m/s). (2)

ii) What is dispersion of light. (2)

c) i) What is the commonly used for electrical energy consumed? Define it. (2)

ii) What is resonance? Give an example of resonance. (2)

d)i) Distinction between real and virtual image. (2)

 

ii) Show, using a ray diagram, how a converging lens can be used to form the virtual image. (2)

e) i) what is the difference between forced and natural vibrations? (2)

ii) with the help of a simple diagram, Show that mechanical advantages of a single fixed pulley is 1 and that of a single movable Pulley is 2. (2)

f) i) give one advantage and one disadvantage of connecting electric cell in a parallel. (2)

ii) state two uses of electromagnets. (2)

g) i) How much does it cost to run one heater of 1000W and two electric bulbs of 40 W each for 8 hours if 1 unit of electricity cost ₹2. (2)

ii) why is it dangerous to use wet hands to put off a switch? what purpose does a fuse serve in a circuit ? (2)

h) i) What is the relation between the joule and calorie; the joule and kilocalorie? (2)

ii) What is meant by the refractive index of a medium with respect to air ? (2)

i) i) What is meant by colour coding of electrical wires ? (2)

ii) What do you understand by the specific latent heat of vaporisation of a substance? (2)

j) i) A pair of pliers and scissors belong to the same class of levers.

A) which one has mechanical advantage less than one?

B) State the usefulness of such a machine? (2)

ii) State the conditions for echoes . (2)

                SECTION - B

(Answer any four questions)

Question 2

a) The diagram (MP1D1) shows a pulley arrangement.

i) In this diagram mark the tensions in the different parts of the string.

ii) What is the velocity ratio ?

iii) If the efficiency is 80%, what is the mechanical advantage?

iv) State two factors that reduce the efficiency. (4)

b) i) What is meant by the internal resistance of a cell? What is its unit ? (4)

ii) The terminal voltage of a cell of e.m.f. 2V is 1.5V. Find the current in the circuit and the internal resistance of the cell if the external resistance is 6 ohms. 

c) Define right hand thumb rule. (2)

Question 3

a) Differentiate between the following:

i) noise and a musical note.

ii) frequency and wavelength of sound. (4)

b) The human ear can detect continuous sounds in the frequency range from 20 Hz to 20000 Hz. Assuming the speed of the sound in air is 330 m/s for all frequencies, calculate the wavelength and corresponding to given extreme to frequencies of the range. (2)

c) Give reasons for the following:

i) the same musical note when played on a piano and when played on a flute sounds different.

ii) soldiers often March 'out of step' while crossing bridges. (4)

Question 4

a) i) The figure shows a smooth cardboard arranged in a horizontal plane with a very small hole in its centre. A vertical wire passes through the hole and is connected to a battery and a key, Redraw the diagram and show the directions of the magnetic field and the current.

ii) Define Potential difference. (4)

b) Define the terms

i) load

ii) effort

iii) mechanical advantage

iv) velocity ratio. (4)

c) A man stands at a distance of 25m from a high wall. He hears the echo off the high wall, produced by a clap of his hands. If the velocity of sound in air is 330 m/s, what would be the time interval between his original clap and hearing of the echo? (2)

Question 5

a)i) Calculate the resistance between the points A and B in the network shown (MP1D3). (2)

ii) What is a simple machine ? Write the relation between load, effort and efficiency. (3)

b) which would be worse, the burn you get holding your hand in a jet of steam or that got from boiling water, both at 100° ? Give a reason for your answer. (2)

c) In an experiment to measure the specific heat capacity of brass, 0.2 kg of hot water, at a temperature 65°C, was poured into a heavy brass container of mass 1.5 kg, initially at 15°C. After steering, the final temperature reached was 45°C. Assume that the specific heat capacity of water is 4200 J/kg/°C.

i) Calculate the heat energy released by the hot water in cooling from 65°C to 45°C.

ii) Assume that the heat energy calculated in part (i) is gained by the brass container in raising its temperature from 15°C to the final common temperature of 45°C. Calculate the heat energy absorbed by the brass container per °C rise in temperature.

iii) using the result obtained in part (iii), Calculate the specific heat capacity of brass. (3)

Question 6

After a robbery, if a window has been broken, there will be tiny particle of glass. Some of these will be found at the scene of the crime and some may be caught in the thief's clothing. If the police can prove that these particles are identical, they have a strong case.

     A method of doing this to suspand the particles of glass in a special liquid. Light of a single colour is shown through the liquid and the particles viewed through a microscope. The temperature of the liquid is then slowly altered. This alters the speed of light through the liquid (i.e., it alters the refractive index). At one particular temperature the particles of glass disappear. if this happens at the same temperature for both sets of glass particles, they probably came from the same broken pane of glass.

a) Complete a copy of the diagram (MP1D4) to show how light bends when it travels from the liquid to the glass and back to the liquid, 

i) If the light slows down the glass.

ii) if the light speeds up in the glass. (4)

b) why is the light used in the police work a single colour ? (2)

c) Under what two circumstances can light moving from a liquid to glass pass straight on without bending ? (2

d) when do the particles of glass disappear in the police method ? (2)

Question 7

The mission of an Alpha particle or emission of Beta particle is nearly always accompanied by what is known as Gamma radiation.

i) How does the ionising power of gamma radiation compare with that of alpha and beta particles ?

ii) Is Gamma radiation more or less penetrating thsn alpha and beta particles?

iii) Is it possible to deflect gamma radiation in the ways that alpha and Beta particles can be deflected, using electric or magnetic fields ?

iv) What is Gamma radiation thought to be ? (4)

b) Radium-226 (²²⁶R⁸⁸) is Radioactive and emits alpha particles.

i) By how much does the atomic number of a radium nucleus (²²⁶Ra⁸⁸) change when an alpha particles is emitted ?

ii) By how much does the mass number of the radium nucleus in part (i) change ?

iii) The new nucleus formed, When a nucleus of ²²⁶Ra⁸⁸ emits an Alpha particle is identified as a nucleus of another element fairly close to radium in the periodic table. identify this element from the data: polonium (Po⁸⁴), (Astatine (At⁸⁵), Radon(Rn⁸⁶) and Francium(Fr⁸⁷). (3)

c) state three major uses of X-rays. (3)