Jamb 2012 Physics Past Questions And Answers
I. Rays of light travel from a less dense medium to a denser medium. II. The Angle of incidence is greater than critical angle. III. Rays of light travel from a denser medium to a less dense medium. Which of the statements above are conditions for total internal reflection to occur?
- A. I & II only
- B. I & III only
- C. II & III only
- D. II only
Which of the following CANNOT be deflected by both electric and magnetic fields?
- A. Gamma rays
- B. Alpha particles
- C. Wave particles
- D. Beta particles
The use of lenses is Not applicable in the
- A. projector
- B. human eye
- C. periscope
- D. telescope
The current output from of an a.c. source is given as I = 10 sin to t. The d.c equivalent of the current is
- A. 5.0A
- B. 7.1A
- C. 10.0A
- D. 14.1A
If a freely suspended object is pulled to one side and released, it oscillates about the point of suspension because the
- A. acceleration is directly proportional to the displacement
- B. motion is directed away from the equilibrium point
- C. acceleration is directly proportional to the square of the displacement
- D. velocity is minimum at the equilibrium ponit
Disperson of white light is the ability of white light to
- A. penetrate air, water and glass
- B. move in a straight line
- C. move around corners
- D. separate to its component colours
A load is pulled at a uniform speed along a horizontal floor by a rope at 45o to floor. If the force in the rope is 1500N, what is the frictional force on the load ?
- A. 1524N
- B. 1350N
- C. 1260N
- D. 1061N
The fuse in an electric device is always connected to the
- A. neutral side of an electric supply
- B. earth side of an electric supply
- C. live side of an electric supply
- D. terminal side of an electric supply
Where can a man place his face to get an enlarged image when using a concave mirror to shave?
- A. Between the centre of curvature and the principal focus
- B. At the principal focus
- C. Between the principal focus and the pole
- D. At the centre of curvature
A piece of radioactive material contains 1000 atmos. If its half -life is 20seconds, the time taken for 125 atoms to remain is
- A. 20 seconds
- B. 40 seconds
- C. 80 seconds
- D. 60 seconds