Physics Past Questions And Answers
The power dissipated in an a.c. circuit with an r.m.s, current of 5A, r.m.s voltage of 10V and a phase angle of 60o is
- A. 25W
- B. 50W
- C. 120W
- D. 125W
A rocket is fired from the earth's surface to a distant planet. By Newton's law of universal gravitation, the force F will
- A. increase as r reduces
- B. increase as G varies
- C. remains constant
- D. increases as r increases
What type of wave is emitted by a loud speaker?
- A. Transverse
- B. Longitudinal
- C. Gamma
- D. Radio
ToC051015204060S.V.P(mmHg)4.586.518.9412.6717.5055.10149.00 The table above shows the saturation vapour pressure against temperature in a certain town. If the vapour pressure in this town at 20oC is 10mmHg, what is the relative humidity?
- A. 170.0%
- B. 57.0%
- C. 17.5%
- D. 10.0%
A bullet fired vertically upwards reaches a height of 500m. Neglecting air resistance, calculate the magnitude of the initial velocity of the bullet. [g = 10ms-2]
- A. 500.0ms-1
- B. 100.0ms-1
- C. 70.0ms-1
- D. 50.0ms-1
A sound note of frequency 250 Hz and wavelength 1.3m is produced at a point near a hill. If the echo of the sound is received 1 second later at the point, how far away is the hill from the point?
- A. 131.3m
- B. 162.5m
- C. 248.7m
- D. 251.3m
A wheel and axle of radii 800mm and 200mm respectively is used to raise a body of weight 800N by the application of 250N. Calculate the efficiency of the machine
- A. 85%
- B. 80%
- C. 60%
- D. 20%
An object placed 10cm from a concave mirror of focal length 5cm would have its
- A) at the centre of convature
- B) at the radius of curvature
- C) at infinity
- D) 10 cm from the focus
The size of the hole of a pin hole camera is increased. The resultant image formed becomes
- A. sharper
- B. reduced in size
- C. enlarged
- D. blurred
The air column in a resonance tube is set into resonance by a vibrating tuning fork. The resultant waves in the air column will be
- A. mechanical and transverse
- B. progressive and longitudinal
- C. stationary and transverse
- D. stationary and longitudinal.

