Name:………………………………………………………..Stream………

UNEB FORMAT

B.O.T. 111 Examination, 2007

S.2 physics

Time: 2 Hours

Instructions:

-Answer all questions in both sections of this paper.

-Section A is made up of 30 objective questions. Write the letter that corresponds to the correct answer in the spaces provided in the table below.

-Section B is made up of 5 numbers.

-Write the answers in the spaces provided for those numbers.

SECTION: A (30 marks)

1 / 11 / 21
2 / 12 / 22
3 / 13 / 23
4 / 14 / 24
5 / 15 / 25
6 / 16 / 26
7 / 17 / 27
8 / 18 / 28
9 / 19 / 29
10 / 20 / 30

1.A dull black surface is a good

  1. absorber of heat energy.
  2. Emitter of heat energy.
  3. Reflector of heat energy

A.i onlyB. i and ii onlyC. ii and iiiD.i, ii and iii

2.Surface tension in a liquid may be weakened by

  1. lowering the temperature
  2. adding soap solution .
  3. Increasing the amount of liquid
  4. Increasing the density of the liquid

3.Radiation is the transfer of heat

  1. in a liquid which involves the movement of the molecules.
  2. From one place to another by means of electromagnetic waves.
  3. Through a material medium without the bulk movement of the medium.
  4. Through a fluid which involves the bulk movement of the fluid itself.

4.When copper sulphate dissolves at the bottom of a water container, it spreads slowly throughout water by a process called.

A.evaporation B. diffusion C. capillarity D. convection

5.When does the eclipse of the moon occur?

  1. When the moon is between the sun and the earth.
  2. When the earth is between the sun and the moon.
  3. When the sun is totally eclipsed by the moon.
  4. When a bright ring of sunlight shows round the edge of the moon.

6.The mode of transfer of heat between the boiler and the storage tank of a hot water supply system is

A.radiation B. conduction C. convection D. evaporation

7.A cork held under water rises to the surface when released because the upthrust on it is

  1. greater than the weight.
  2. Less than the weight.
  3. Equal to the weight.
  4. Equal to the weight of water displaced.

8.The distance between the fixed points on a mercury in glass thermometer is 25cm. What is the temperature in degrees celcius if the mercury thread is 8cm long?

A.100 x 25B. 25 x 8C. 100 x 8D. 100

8 100 25 25 x 8

9.Soap is used to wash clothes because it

  1. increases capillarity in the clothes.
  2. Reduces capillarity in the clothes.
  3. Increases surface tension allowing water to penetrate the dirt easily.
  4. Reduces surface tension allowing water to penetrate the dirt easily.

10.An object is placed 30cm infront of a plane mirror. If the mirror is moved a distance of 6cm towards the object. Find the distance between the object and its image.

A.24cmB. 36cmC. 48cmD. 60cm

11.The transfer of heat by the actual movement of molecules of matter takes place.

A.only in liquids B.only in gases

C.in solids and liquids D.in liquids and gases.

12.In a liquid, pressure is;

A.transmitted in a specific direction B. transmitted in all directions.

C.Decreased with depthD. decreased with density.

13.A set of apparatus that is suitable for measurement of the volume of an irregular object includes;

  1. overflow can, measuring cylinder , irregular object and string.
  2. Measuring cylinder , irregular object, overflow can, flask.
  3. Overflow can, irregular object, string retort stand and burette.
  4. Burette, overflow can, irregular object string, measuring cylinder , retort stand.

14.Brownian motion experiment shows that molecules of gases are;

  1. stationary.
  2. In motion in one direction only.
  3. In constant random motion.
  4. More closely packed than molecules in liquid.

15.A stone flow feels very cold to bare feet in cold weather , but a carpet in the same room feels comfortably warm. Why is this so?

  1. The stone is a worse conductor of heat than a carpet.
  2. The stone is a better conductor of heat than a carpet.
  3. The carpet is a better conductor of heat than a stone.
  4. The stone is a better reflector of heat than the carpet.

16.An oil drop of volume 103 cm3 forms a patch on water. The area of the patch is 0.785cm2.

If it is one molecule thick, what is the size of the molecule?

A.4.06 x 10-4cm B. 7.85 x 10-4cmC. 9.53 x 10-4cmd. 1.27 x 10-3 cm

17.Pressure in a liquid is independent of the

  1. density of the liquid
  2. depth below the surface of the liquid.
  3. Pressure exerted on the surface of the liquid above.
  4. Cross – sectional area and the shape of the vessel containing the liquid.

18.When mercury is spilt on glass, it forms small spherical droplets because its

  1. density is high.
  2. Surface tension makes its surface elastic.
  3. Molecules are small.
  4. Cohesive force is greater than adhesive force with glass.

19.The energy changes involved in an electric generator are;

  1. electrical to chemical
  2. potential energy to chemical energy.
  3. Chemical to light energy.
  4. Kinetic energy to electrical energy.

20.The graph below shows ice being heated from –10oC to 100oC.

V/m3

B E

C

A

D

-10 0 100 Temperature/oC

At what point does the substance have maximum density?

A.EB. CC. DD. B

21.The process of using a material of low thermal conductivity to prevent heat loss is called.

A.cooling B. lagging C. absorption D. contraction

22.The weight of a body of dimensions 4m x 2m x 3 is 480N. The minimum pressure it can exert is;

A.20Nm-2B. 40nm-2C. 60Nm-2D. 80Nm-2

23.A magnetic material can be magnetized by

  1. stroking with a permanent magnet.
  2. Induction
  3. Using alternating current.

A.i onlyB. i and ii onlyC. ii and iii onlyD. i, ii and iii only.

24.Length, mass and current are;

  1. units of measurements
  2. derived quantities.
  3. Fundamental quantities.
  4. Measured in metres, Newtons and amperes respectively.

25.Convert 25cm3 into m3.

A.2.5 x 105B. 2.5 x 102C. 2.5 x 10-1D. 2.5 x 10-5

26.What is 730mmhg in Nm-2?

A.13600 x 1000 x10B.13600 x 730 x 10C. 13600 x 730D. 13600 x 10

7301000 1000 x 10 1000 x 730

27.A bimetallic strip operates on the principle that metals.

  1. are heat controllers.
  2. Are good heat conductors.
  3. Have different rates of expansion.
  4. Have the same rates of expansion.

28.A sea breeze occurs,

  1. When cool air blows towards the land.
  2. When warm air blows towards the land.
  3. During the night.
  4. When cool air blows towards the sea.

29.In a hydraulic machine

  1. an object displaces its own weight of fluid.
  2. The pressure transmitted in a fluid is eh same in all directions.
  3. The volume of fluid compressed is proportional to the applied force.
  4. An object experiences an upthrust equal to the weight of fluid displaced.

30.A hippopotamus can easily walk on mud without sinking while a goat will sink because

  1. a hippopotamus has more weight than a goat.
  2. The centre of gravity of a hippopotamus is lower than that of a goat.
  3. A hippopotamus exerts more pressure on the ground than a goat.
  4. A hippopotamus exerts less pressure on the ground than a goat.

SECTION ; B (20 marks)

31.a)State Archrnedes principle.(1mark)

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b)A solid weights 25N in air and 19N when submerged in water. Find the density of the material of the solid .(Density of water = 1000kgm-3) (3marks)

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32.a)State any two factors which affect pressure in liquids.(1mark)

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b)The diagram below shows an instrument used for measuring gas pressure in a laboratory.

Find the pressure in Nm-1 of the gas if atmospheric pressure is 70cmHg (Density of mercury = 13600Kg/m3) (3marks)

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33.

The above fig. shows a thermos flask.

a)Name parts labelled (1mark)

A……………………………………………B………………………………….

b)State the use of the part labelled A.(1mark)

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c)Why do the contents of the flask ultimately get cold?(2marks)

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34.Copper

Iron

The fig. shows strips of copper and iron bonded together.

a)Redraw the diagram to show what happens when the strip is heated. (1mark)

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b)Why does the change you have shown in (a) take place?

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c)State two appliances where the above effect is applied .(2marks)

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35.a)State the principle of floatation.(1mark)

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b)A cube of edge 0.1m floats in a liquid of density 1200Kgm-3 with a third of it submerged, find the density of the material of the cube.

(density of water = 1000kgm-3)(3marks)

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