Third Term Examination
Class : SSS 1
Subject : Physics
Duration : 2 Hours
Section A : Objective Questions
Instruction : Read the question and choose from the alternatives lettered a – d.
1. Which of the following is not a fundamental S. I unit? (a) Metre (b) Ampere (c) Kelvin (d) Radian
2. The shape of a straight line displacement – time graph indicates (a) Distance traveled (b) uniform velocity (c) uniform acceleration (d) acceleration at an instant
3. A man of mass 50kg ascends a flight of stairs 5m high in 5seconds. If acceleration die to gravity is 10m/s², the power expanded is ________. (a) 500W (b) 200W (c) 250W (d) 400W
4. If no net force act on an object, the object maintains a state of rest or constant speed in a straight line. The above is a statement of Newton’s ___________. (a) First law (b) Second law of motion (c) third law of motion (d) law of universal
5. Three 3.0 ohm resistors are connected in parallel. What is the equivalent resistance? (a) 9.0 ohm (b) 3.0 ohm (c) 1.0 ohm (d) 0.33 ohm
6. An electric lamp is marked 240 volts, 60 watts. What is its resistance when it is operated at correct voltage? (a) 1/960 (b) 1/4 (c) 4 (d) 960
7. The increase in the volume of 10cm³ of mercury when the temperature rises by 100°c is 0.182cm³. What is the cubic expansivity of mercury? (a) 0.000182k-¹ (b) 0.0000183k-¹ (c) 0.009178k-¹ (d) 0.000187k-¹
8. A brass rod is 2m long at a certain temperature. What is its length for a temperature rise of 100K if the expansivity of brass is 18 x 10^-6 k-¹ (a) 2.0036m (b) 2.0018m (c) 2.1800m (d) 2.036m
9. A room is heated by means of a charcoal fire. A man standing away from the fire is warmed by ___________. (a) conduction (b) reflection (c) radiation (d) convection
10. Two resistors 5.0 ohm each can be combined to give an equivalent resistance of : i. 10.0 ohm ii. 25 ohm iii. 2 50 ohm iv. 0.25 ohm. Which of the following alternative is correct? (a) I only (b) I and II (c) I and III (d) I and IV
11. The head lamp of a car takes a current of 0.4 ampere from 12 volt supply. The energy produced in 5minutes is __________. (a) 24J (b) 240J (c) 288J (d) 1440J
12. On which of the following is the design of thermostat of an electric iron based? (a) apparent expansion of a body (b) thermoelectric effect (c) expansion of metals when heated (d) change in the resistance of a body on heating.
13. Which of the following surfaces will absorb radiant heat energy best? (a) white (b) red (c) yellow (d) black
14. Which of the following thermometers responds best to changing temperature? (a) Mercury thermometer (b) Alcohol thermometer (c) Resistance thermometer (d) thermoelectric thermometer
15. Which of the following instrument can be used to compare the relative magnitude of charge on two given bodies? (a) ebonite rod (b) proof blanes (c) the electrophone (d) gold-leaf electroscope
16. When charging an insulated conductor by induction, the following steps are usually taken.
i. Bring a charged body near to the conductor.
ii. Remove the charged body.
iii. Touch the conductor with a finger
iv. Remove the finger
What is the correct sequence in this activity? (a) I, II, III, IV (b) I, III, IV, II (c) I, IV, III, II (d) III, IV, I, II
17. A glass rod rubbed with silk becomes positively charged because _______________. (a) some positive charges are transferred from the silk to the glass (b) some electrons are transferred from silk to the glass (c) the silk becomes deficient in electrons (d) some electrons have been transferred from glass to silk.
18. A thermometer has its stem marked in millimeter instead of degree Celsius. The lower fixed point is 30mm and the upper fixed point is 180mm. Calculate the temperature in degree Celsius when the thermometer reads 45mm. (c) 67.5°C (b) 30.0°C (c) 25°C (d) 15.0°C
19. Calculate the total energy developed in 5minutes by the system above. (a) 120 J (b) 144 J (c) 240 J (d) 8640 J
20. It is known that a neutron exist in a light atomic nucleus. Which of the following also exist in the nucleus? (a) An electron (b) A B – particle (c) An X – particle (d) A proton
21. Which of the following statements is not correct? (a) Matter is made up of molecules (b) Brownian motion is an evidence of particle nature of matter (c) molecules of liquid are stationary (d) Atoms combine to form molecules
22. A spring 20cm long is stretched to 25cm by a load of 50N. What will be its length when stretched by 100N assuming that the elastic limit is not reached? (a) 30cm (b) 10cm (c) 35cm (d) 40cm
23. An elastic cord can be stretched to it’s elastic limit by a load of 2N. If a 35cm length of the cord is extended 0.6cm by a force of 0.5N. What will be the length of the cord when the stretching force is 2.5N? (a) 350.8 cm (b) 352. 8cm (c) 353.0cm (d) cannot be determined from the data given.
24. The action of bolting paper on ink is due to __________. (a) diffusion (b) osmosis (c) capillary (d) surface
25. The meniscus of water in a capillary tube is (a) convex (b) concave (c) straight (d) dependent on the bore of the tube
26. In which of the following is surface tension important? (a) the floating of a ship in water (b) the floating of a dry needle in water (c) the floating of a balloon in air (d) the diffusion of sugar solution across a membrane
27. The rise or fall of a liquid in a narrow tube is due to _________. (a) the friction between the walls of the tube and the liquid (b) the viscosity of the liquid (c) the osmotic pressure of the liquid (d) the surface tension of the liquid
28. In the drawing above, V is the viscosity and U is upthrust. Which of the following equation holds when the falling body P has attained a terminal velocity? (a) V + mg = U (b) V + U – MG = 0 (c) V = mg/ U (d) V – U = mg
29. Which of the following factors may be used to explain why a steel pin may float in water? (a) The force of cohesion between the pin and water (b) The force of adhesion between the pin and water (c) The surface tension of water (d) The law of floatation
30. Which of the following explains the concave meniscus of water in a glass tube? (a) The adhesion between water and glass is greater than the cohesion between water molecules (b) the cohesion between water molecules is greater than the adhesion between glass and water (c) The molecules of water near the glass are moving faster than the molecules in the outer parts (d) the molecules of water at the water- air boundary are often attracted to the center of the tube
31. A spring of force constant 1500Nm-¹ is acted upon by a constant force of 75N. Calculate the potential energy stored in the spring. (a) 1.9 J (b) 3.2 J (c) 3.5 J (d) 5.0 J
32. A Catapult is used to project a stone. Which of the following energy conversions takes place as the stone is released? (a) The kinetic energy of the stone is converted into gravitational potential (b) The gravitational potential energy is converted into kissing metic energy of the stone (c) The elastic potential energy of catapult is converted into kinetic energy of the stone.(d) The gravitational potential energy is converted into elastic potential energy
33. A spring balance classified for a maximum like ad of 400N was used to weigh a load of 500N. After the 500N load had been removed, the pointer would not return to the zero mark on the scale because. (a) spring balance was of the cheap type (b) elastic limit of the spring material had been exceeded. (c) the pointer was not properly adjusted (d) there was too much draughts of air in the room.
34. Three resistors resistances 1 ohm, 2ohm and 4 ohm are connected in series, the equivalent resistance of the combination is (a) 17 ohm (b) 7 ohm (c) 4/7 ohm (d) 7/4 ohm
35. If three resistance 2 ohm, 3 ohm and 5ohm are connected in parallel in a circuit, the equivalent resistance of the combination is (a) 10 ohm (b) 0.97 ohm (c) 9.70 ohm (d) 0.1 ohm
36. The equivalent resistance of the above connection is (a) 3.8 ohm (b) 8 ohm (c) 3 ohm (d) 8.3 ohm
37. A spring is stretched 40m by a force of 15N. What is the work done by the force? (a) 0.3 J (b) 3 J (c) 30 J (d) 300 J
38. A car traveled a distance of 4km in 40 sec. Find the speed of the car in Metre per second (m/s). (a) 50m/s (b) 100m/s (c) 150m/s (d) 1000m/s
39. Which of the following quantities has the same unit as energy? (a) power (b) work (c) force (d) momentum
40. Which of the following is an evidence of particle nature of matter? (a) Diffusion (b) Brownian motion (c) Diffraction (d) Crystallization
41. Which of the following has the highest surface tension? (a) cold water (b) soapy water (c) warm water (d) oily water
42. Which of the following is not a consequence of force field? (a) weight (b) surface tension (c) electric force (d) gravitational pull
43. A car fuse marked 3A operates optimally on a 12v battery. Calculate the resistance of fuse. (a) 360 L (b) 150 L (c) 90 L (d) 40 L
44. Which of the following factors dies not affect the electric resistance of a wire? (a) length (b) mass (c) temperature (d) cross – sectional area
45. A positively charged rod is placed near a cap of a positively charged electroscope. The divergent f the leaf is observed to __________ (a) decrease (b) increase (c) remain the same (d) increase and collapse immediately
46. A steel needle floating on water sinks when kerosene is added to the water. This is because the kerosene (a) increases the surface tension of the water (b) reduces the surface tension of water (c) reduces the density of water (d) reduces the upthrust on the needle
47. The greatest charge density is at point (a) 1 (b) 2 (c) 3 (d) 4
48. A short chain is usually attached to the back of a petrol tanker trailing behind it to ensure that the _________. (a) petrol tanker is balanced on the road (b) heat generated by friction in the engine can be conducted to the floor (c) charges generates by friction in the tanker is conducted to the earth (d) tanker moves slowly as the chain touches the road surface
49.
Section B : Theory
Instruction : Answer question 1 and any other two questions.
1. A television (65W), a refrigerator (1.2KW), an electric kettle (650W) and 10 lamp (40W) each are connected in series in a house. How much will it cost the house keeper to switch on all the appliances for 24hours if the cost of electricity is 15kobo per Kw/h?
2a. Distinguish between crystalline and amorphous substances give two examples of each.
2b. The ices and steam point on a thermometer are found to be 96.0mn apart. What temperature is recorded when the length of mercury there is 33.6mm above the ice point mark?
3a. What is surface tension?
b. Explain the phenomenon in terms of intermolecular forces.
c. Why does water wet clean glass surfaces whereas mercury does not?
d. State two method by which the surface tension of a liquid may be reduced.
4a. State Hooke’s law
b. A stone of mass 5g is protected with a rubber catapult. If the catapult is stretched through a distance of 7cm by an average force of 79N. Calculate the instantaneous velocity of the stone when released.
5a. Distinguish between
i.) Distance and displacement
ii.) Speed and velocity
b.) Define linear expansivity of a solid.
c.) A solid metal cube of side 10cm is heated from 10°c to 60°c. If the linear expansivity of the metal is 1.2 x 10^-5k-¹. Calculate the increase in its volume.