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
80.0W
40.0W
10.0W
0.1W
Correct answer is A
Power input = 3KW = 3000W
Voltage = 1.5KV = 1500V
Current (I) = P/V = 3000/1500 = 2Amps.
∴ Power loss in the cables = I2R
= 2 x 2 x 20
= 80W