Physics Past Questions And Answers
The colours of the visible light region of the electromagnetic spectrum that have the shortest and longest wavelengths respectively are
- A. red and blue.
- B. indigo and violet
- C. violet and red.
- D. yellow and blue.
A cell of emf 2 V has an internal resistance of 0.5 Ω. A current of 0.4 A passes through an external resistor, P. Determine the resistance of P.
- A. 4.5Omega;
- B. 5Omega;
- C. 1Omega;
- D. 4Omega;
During a thunderstorm, the sound is heard over a long time. this phenomenon is referred to as
- A) diffraction of sound
- B) refraction of sound
- C) superposition
- D) reveraberation
When a conductor mounted on an insulating stand is charged and left for sometime, the conductor eventually loses all its charges. This is because the
- A. electric charges evaporate from the surface of the conductor
- B. charges are connected to earth
- C. charges on the conductor are neutralized by opposite charges from the surrounding air
- D. charges ionize the surrounding air
Which of the following optical instruments does not depend on the use of plane mirrors?
- A. kaleidoscope
- B. simple microscope
- C. sextant
- D. simple periscope
A piece of iron weights 250 N in air and 200 N in a liquid of density 1000 kgm-3. the volume of the iron is?
- A) 5.0 x 10-2 ms-2
- B) 4.5 x 10-2 ms-3
- C) 2.5 x 10-2 ms-8
- D) 2.0 x 10-2 ms-3
An engineer intends to deviate a light ray from its path by 120° through reflection from a plane mirror. Calculate the angle of incidence
- A. 60°
- B. 40°
- C. 30°
- D. 20°
Which of the following phenomena is the practical evidence for the existence of the continual motion of molecules?
- A. Translational motion
- B. rotational motion
- C. brownian motion
- D. oscillatory motion
In the circuit diagram of a transistor below, the terminal P, Q and R represent
- A. EMITTER, BASE and COLLECTOR
- B. COLLECTOR, EMITTER and BASE
- C. BASE, COLLECTOR and EMITTER
- D. BASE, ENITTER and COLLECTOR
Which electrical device is illustrated above?
- A. a.c. generator
- B. a.c. motor
- C. d.c. generator
- D. d.c. motor