Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
alternating current at low voltage and high current
alternating current at high voltage and high current
alternating current at high voltage and low current
direct current at low voltage and high current
Correct answer is C
No explanation has been provided for this answer.
The core of a transformer is usually laminated in order to
reduce magnetic leakage
reduce eddy current
prevent vibration of the transformer
make magnetic reversal in the core much easier
Correct answer is B
No explanation has been provided for this answer.
The magnetic relay is a device used for
timing in sports
storing magnetic field
reading the magnitude of magnetic flux
controlling another circuit carrying larger current
Correct answer is D
No explanation has been provided for this answer.
A 12\(\Omega\) resistor dissipates 8kJ of heat in 20s. Calculate the current through the resistor
5.8A
6.9A
30.0A
33.3A
Correct answer is A
Q = I2Rt
I = \(\sqrt{\frac{Q}{Rt}}\)
= \(\sqrt{\frac{8000}{12 \times 20}}\)
= 5.8
P
Q
R
S
Correct answer is B
The determinant of the brightness of a bulb is the power (watts) of the circuit.
Recall that Power (P) = \(\frac{V^2}{R}\).
Since the resistance is to be used as a divisor, it means the smaller the resistance, the greater the power.