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.
25%
33%
50%
75%
Correct answer is D
Efficiency = Output/input x 100/1
Efficiency = 3/(3+1) x 100/1
= 3/4 x 100/1 = 75%
200 Ω
50 Ω
100/π Ω
25/π Ω
Correct answer is A
Inductive reactance is given by
XL = WL = 2πfL
XL = 2 x π x (50/π) x 2
XL = 200Ω
beta rays
gamma rays
x-rays
ultra-violet rays
Correct answer is A
No explanation has been provided for this answer.
24 years
20 years
10 years
2 years
Correct answer is B
1/64 is the usual fraction left of any radio active material after 4 half-lives, since 1/64 = (1/2)6
This implies that 6 half lives have elapsed.
Thus 6 half lives = 120 years
∴ 1 half life = 120/6 = 20 years
6630.0V
663.0V
66.3V
6.6V
Correct answer is C
Energy imparted by the accelerating system = e x V, where V is the accelerating potential; and this energy is equal to the energy of the X-ray, give by hf
e x V = hf
∴ V = hf/e
(6.63 x 10\(^{-34}\) x 1.6 x 10\(^{16}\))/1.6 x 10\(^{-19}\)
= 6.63 x 10 = 66.3V