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.
\( \frac{1}{32} \)
\( \frac{1}{16} \)
\( \frac{1}{8} \)
\( \frac{1}{4} \)
Correct answer is B
80 days = 4 half lives (i.e 4 x 20dqs = 80dq)
But the fraction always left by any radioactive material after 4 half lives is
\( \left ( \frac{1}{2} \right)^4 = \frac{1}{16} \)
100 Ω
200 Ω
300 Ω
500 Ω
Correct answer is B
Power of the lamp = 60W = (V2)/R and the voltage rate = 120v.
R = (V2)/60 = (120 X 120)/60 = 240 Ω, the fuse wire that should ensure current does not exceed this value should be rated 200 Ω
The instrument that measures both a.c and d.c is?
a current balance
a moving current ammeter
a moving iron ammeter
an inverter
Correct answer is C
No explanation has been provided for this answer.
4.0 x 102W
5.0 x 102W
4.0 x 103W
5.0 x 103W
Correct answer is D
In general, power = IV; 40kw = IV.
∴ 40,000 = 1 x 800
1 = (40.000)/800 = 50A. tune the current through resistor = 50A.
∴ power loss = 12R = 502 X 2 = 2500 X 2 = 5.0 X 103W
2.55 x 105 Ωm
2.55 x 102 Ωm
3.93 x 10-6 Ωm
3.93 x 10-8 Ωm
Correct answer is D
R = (1)/a, P = (R.a)/1 = (0.1 x 3.14)/2 (10-3/2)3
∴ P = (0.1 x 3.14 x 10-6)/2 x 4
= 0.3925 x 10-7 OR -3.930 X 10-8 Ωm