5.0 x 1016 Hz
2.0 x 1016 Hz
5.0 x 1015 Hz
2.0 x 1015 Hz
No correct option
Correct answer is E
∆E = hf
f = (∆E)/h = (5.44 x 10-19)/6.6 x 10-34 = 8.24 x 1014
In a discharge tube, most of the gas is pumped out so that electricity is conducted at?
low voltage
steady voltage
high pressure
low pressure
Correct answer is C
pumping out of the gas in the discharge tube reduces the pressure inside the tube, therefore, electricity is conducted at low pressure
In alternating current circuit at resonance, the angle of lead or lag is?
π°
(π)/2°
(π)/3°
0°
Correct answer is D
Resonance occurs whenever the phase angle of the circuit is zero, The only way that f = 0 is if XL = XC
500.0J
250.0J
62.5J
50.0J
Correct answer is E
Total inductance,L = L1 + L2 = m
15 + 5 = 20mH = (20)H/1000
1 = 5A
Energy of inductor, (1)/2 L I2
= (1)/2 X (20)/1000 X 5-2
= 0.25 J
1Ω
2Ω
5Ω
10Ω
Correct answer is B
r = resistance of the galvanometer
l = current through galvanometer = 1mA or 0.01A
V1 = p.d across the galvanometer = I X r = 0.01 X r
: V1 = 0.01r
V2 = p.d across the multiplier = 5 - 0.01r
R = resistance of the multiplier = 498Ω
where R = \(\frac{V}{I}\) --> 498 = \(\frac{5 - 0.01r}{0.01}\)
CROSS MULTIPLY --> 498 X 0.01 = 5 - 0.01r
0.01r = 5 - 4.98
∴ r = \(\frac{0.02}{0.01}\) = 2Ω