2012 - WAEC Physics Past Questions and Answers - page 4
31
Which of the following sets of coloured light is/are secondary colours i. Red, Blue and green ii. Blue, cyan and magneta iii. Green, Magenta and yellow, IV Yellow, Cyan and Magenta
A
i and ii only
B
ii and iii only
C
iv only
D
i, ii and iv only
Ask EduPadi AI for a detailed answer
Share this question
32
When two like charges are brought together, the potential energy of the system formed will
A
increase because work is done against the field
B
increase because work is done by the field
C
decrease because work is done by the field
D
decrease because work is done against the field
Ask EduPadi AI for a detailed answer
Share this question
33
Two capacitors, each of capacitance 2\(\mu\)F are connected in parallel. If the p.d across them is 120V, calculate the charge on each capacitor
A
6.0 x 10-5C
B
1.2 x 10-4C
C
2.4 x 10-4C
D
4.8 x 10-4C
Ask EduPadi AI for a detailed answer
Share this question
34
Which of the following properties is an advantage of lead-acid accumulator over an alkaline accumulator?
A
possesses low internal resistance
B
can be recharges
C
has shorter life span
D
possesses high e.m.f
Ask EduPadi AI for a detailed answer
Share this question
35
Six dry cells each of e.m.f. 2.0 and internal resistance of 1.0\(\Omega\) are connected in parallel across a load of 3.0\(\Omega\). Calculate the effective current in the circuit
A
0.63A
B
0.50A
C
0.31A
D
.22A
Ask EduPadi AI for a detailed answer
Share this question
36
Two similar cells are used to light two similar lamps as illustrated in the diagrams above. In which of the circuit diagrams are the lamps brightest?
A
P
B
Q
C
R
D
S
Ask EduPadi AI for a detailed answer
Share this question
37
A 120\(\Omega\) resistor dissipates 8 kJ of heat in 20s. Calculate the current through the resistor
A
5.8A
B
6.9A
C
30.0A
D
33.3A
Ask EduPadi AI for a detailed answer
Share this question
38
The magnetic relay is a device used for
A
timing in sports
B
storing magnetic field
C
readin the magnitude of magnetic flux
D
controlling another circuit carrying larger current
Ask EduPadi AI for a detailed answer
Share this question
39
the core of a transformer is usually laminated in order to
A
reduce magnetic leakage
B
reduce eddy current
C
prevent vibration of the transformer
D
make magnetic reversal in the core much easier
Ask EduPadi AI for a detailed answer
Share this question
40
Which of the following modes is the most economical method of transmitting electrical power over long distances?
A
alternating current at low voltage and high current
B
alternating current at high voltage and high current
C
alternating current at high voltage and low current
D
direct current at low voltage and high current
Ask EduPadi AI for a detailed answer
Share this question