31. An electron of mass 9.1 x 10−31kg moves with a speed of 2.0 x 106ms−1 round the nucleus of an atom in a Circular path of radius 6.1 x 1011 Calculate the centripetal force acting on the electron.
- A. 7.7 x 1047 N
- B. 6.0 x 10−8N
- C. 3.0 x 10−14N
- D. 1.3 x 10−26N
32. A device consumes 100 W of power when connected to a 120 V source. Calculate its resistance.
- A. 1.2Ω
- B. 12,000 Ω
- C. 20.0Ω
- D. 144Ω
33. Which property of a wave remains constant when the wave travels from one medium into another?
- A. Amplitude
- B. Wavelength
- C. Velocity
- D. Frequency
34. The anomalous expansion of water occurs in the range
- A. 0 °C to 100 °C
- B. 0 °C to 4 °C
- C. 4 °C to 100 C
- D. -4 °C to 0 °C
35. A ray of light travelling from a rectangular glass block of refractive index 1.5 into air strikes the block at an angle of incidence of 30. Calculate its angle of refraction.
- A. 48.6°
- B. 19.5°
- C. 20.0
- D. 45.0
36. A rectangular piece of iron measuring 4 cm by 3 cm at 20oC is heated until its temperature increases by 100 C. Calculate the new area of the metal. [Linear expansivity of iron is 1.2x 10−5K−1]
- A. 12.0144 cm3
- B. 12.0346 cm3
- C. 12.0288 cm3
- D. 12.0173 cm3
37. Which of the following graphs gives the correct relationship between energy and mass when mass is converted to energy?
- A. A
- B. B
- C. C
- D. D
38. The diagram above illustrates an object moving in a circular path at a constant speed. Which of the arrows indicates the direction of linear velocity?
- A. z
- B. X
- C. Y
- D. W
39. Which of the following thermometers is used to measure the temperature of the human body?
- A. Thermocouple
- B. Alcohol-in-glass thermometer
- C. Gas thermometer
- D. Platinum resistance thermometer
40. In the diagram above, the time taken to trace a wave between P and Q is
- A. 2 periods
- B. 1 period
- C. 1 1/2 periods
- D. 1 1/4 periods
41. Which of the following materials does not serve as a safety device in electrical circuits?
- A. Connecting wires
- B. Earth wire
- C. Fuse
- D. Switch
42. Which of the following liquids has the highest surface tension?
- A. Soapy water
- B. Cold water
- C. Hot water
- D. oily water
43. The nucleon and proton numbers of a neutral atom of an element are 238 and 92 respectively. Determine the number of neutrons in the atom.
- A. 119
- B. 330
- C. 165
- D. 146
44. An instrument used to measure relative humidity is the
- A. hygrometer
- B. hydrometer
- C. pyrometer
- D. manometer
45. The area under a velocity-time graph represents
- A. speed
- B. acceleration
- C. moment
- D. distance
