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.
2A
5A
10A
20A
Correct answer is D
The maximum current drawn by the cooker is given by;
I = \(\frac{P}{V}\)
∴ I = \(\frac{\text{3000}}{200}\)
I = 15A
The fuse rating = I \(\times\) 125% (the fuse is rated at 125% of the normal operating current)
Hence, the fuse rating = 15A \(\times\) (\(\frac{125}{100}\)) = 18.75amps
Therefore, the best fuse is 20A.
6.0V, 16Ω
6.0V, 1Ω
1.5V, 4Ω
1.5V, 1Ω
Correct answer is D
Since all the cells are connected in parallel, the effective e.m.f. is just that of one single cell. Which means e.m.f. = 1.5V
However, the effective internal resistance adds as parallel arrangement given as
1/r = 1/r1 + 1/r2 + 1/r3 + 1/r4
= 1/4 + 1/4 + 1/4 + 1/4
= 1Ω
∴ r = 1Ω
Answer = 1.5V, 1Ω
Steel is more suitable for permanent magnet than iron because the former
is easily demagnetized by shaing vigorously
is an alloy of many metals
is easily magnetized by alternating current through one cycle
retains magnetism more than iron
Correct answer is D
No explanation has been provided for this answer.
Which of the following electromagnetic waves is least energetic?
Infra-red rays
X-rays
Ultra-violet rays
Gamma rays
Correct answer is A
No explanation has been provided for this answer.
An astronomical telescope is said to be in normal adjustment when the
eye is accommodated
focal length of objective lens is longer than that of eye piece
final image is at the near point of eye
final image is at infinity
Correct answer is D
No explanation has been provided for this answer.