The time required for a 50 Hz sinusoidal alternating current to change its value from zero to the r.m.s. value will be:
1.
2.
3.
4.
In a series RLC circuit, potential differences across R, L and C are 30 V, 60 V and 100 V respectively, as shown in the figure. The emf of the source (in volts) will be:
1. 190
2. 70
3. 50
4. 40
In a series LCR circuit, the phase difference between voltage across L and voltage across C is equal to:
1. | Zero | 2. | \(\pi\) |
3. | \(\pi \over 2\) | 4. | \(2\pi\) |
The variation of EMF with time for four types of generators is shown in the figures. Which amongst them can be called AC voltage?
(a) | (b) |
(c) | (d) |
1. | (a) and (d) |
2. | (a), (b), (c), and (d) |
3. | (a) and (b) |
4. | only (a) |
Calculate the Q-value of a series LCR circuit with L = 2.0 H, C = 32 μF and R = 10 \(\Omega\).
1. 35
2. 20
3. 15
4. 25
An AC voltage source is connected to a series \(LCR\) circuit. When \(L\) is removed from the circuit, the phase difference between current and voltage is \(\frac{\pi}{3}\). If \(C\) is instead removed from the circuit, the phase difference is again \(\frac{\pi}{3}\) between current and voltage. The power factor of the circuit is:
1. \(0.5\)
2. \(1.0\)
3. \(-1.0\)
4. zero
In an L-C-R series AC circuit, the voltage across each of the components - L, C and R is 50 V. The voltage across the L-R combination will be:
1. 50 V
2. \(50 \sqrt{2} ~V\)
3. 100 V
4. 0 V
An ideal resistance R, ideal inductance L, ideal capacitance C, and AC voltmeters are connected to an AC source as shown. At resonance:
1. | Reading in \(V_3\) = Reading in \(V_1\) |
2. | Reading in \(V_1\) = Reading in \(V_2\) |
3. | Reading in \(V_2\) = Reading in \(V_4\) |
4. | Reading in \(V_2\) = Reading in \(V_3\) |
A direct current of \(5~ A\) is superimposed on an alternating current \(I=10sin ~\omega t\) flowing through a wire. The effective value of the resulting current will be:
1. | \(15/2~A\) | 2. | \(5 \sqrt{3}~A\) |
3. | \(5 \sqrt{5}~A\) | 4. | \(15~A\) |
The r.m.s. value of the potential difference V shown in the figure is:
1.
2.
3.
4.