Physics Past Questions And Answers
A chemical cell of internal resistance 1\(\Omega\) supplies electric current to an external resistor of resistance 3\(\Omega\). Calculate the efficiency of the cell
- A. 75%
- B. 50%
- C. 33%
- D. 25%
The nucleon number and the proton number of a neutral atom of an element are 238 and 92 respectively. What is the number of neutrons in the atom?
- A. 330
- B. 238
- C. 146
- D. 119
A generator manufacturing company was contracted to produce an a.c dynamo but inadvertently produced a d.c dynamo. To correct this error, the
- A. armature coil should be made of silver
- B. commutator should be replaced with slip ring
- C. commutator should be replaced with split rings
- D. armature coil should be made of aluminium
The value of the e.m.f of a voltaic cell, which has dilute tetraoxosulphate (VI) acid as its electrolyte and copper and zinc as its electrodes becomes less with use. Explain this observation and state how it can be corrected.
View Discussion (0)WAEC 2001 THEORYIf the charge of electricity is K wh is N4, what is the cost of operating an electrical appliance rated 250 v,2 A for six hours?
- A) N28
- B) N12
- C) N16
- D) N24
Which of the following devices may be used to step up the voltage in a d.c. circuit?
- A. a step-up transformer
- B. a d.c. generator
- C. a wattmeter
- D. an induction coil
Transistors are used for the
- A) rectification of signals
- B) conversion of a.c to d.c
- C) amplification of signals
- D) conversion of d.c to a.c
A wave of weight length 0.30m travels 900m in 3.0s, calculate its frequency
- A. 68.0Hz
- B. 225.0Hz
- C. 1000Hz
- D. 750.0Hz
A note of frequency 2000Hz has a velocity of 400 ms-1. calculate the wavelength of the note
- A. 5.0m
- B. 2.0m
- C. 0.5m
- D. 0.2m
Which of the following statements about pressure in a liquid is correct?
- A. the pressure in a liquid increases with depth
- B. the higher the density of a liquid, the lower the pressure it exerts
- C. pressure in liquid act only in a direction perpendicular to the sides of the containing vessel
- D. pressure is independent of the acceleration due to gravity