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)

The peak value of an alternating e.m.f. $\mathrm{E}={\mathrm{E}}_0 \sin \mathrm{\omega t}$ is 10 volt and its frequency is 50 Hz. At a time \(t=\frac{1}{600}~s,\) the instantaneous value of the e.m.f. will be:

1. 1 volt

2. $5\sqrt{3}$ volt

3. 5 volt

4. 10 volt

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. $1.5\times {10}^{-2} \mathrm{s}$

2. $2.5\times {10}^{-3} \mathrm{s}$

3. ${10}^{-1} \mathrm{s}$

4. ${10}^{-6} \mathrm{s}$

A sinusoidal supply of frequency 10 Hz and r.m.s. voltage of 12 V is connected to a 2.1 $\mathrm{\mu F}$ capacitor. What is the r.m.s. value of current?

1. 5.5 mA

2. 20 mA

3. 26 mA

4. 1.6 mA

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 e.m.f. 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. $\mathrm{\pi }$

3. $\frac{\mathrm{\pi }}{2}$

4. $2\mathrm{\pi }$

In a series LC circuit, if $\mathrm{L}={10}^{-3 }\mathrm{H}$ and $\mathrm{C}=3\times {10}^{-7} \mathrm{F}$ is connected to a 100 V-50 Hz a.c. source, the impedance of the circuit is:

1. $\frac{{10}^5}{3\mathrm{\pi }}-10\mathrm{\pi }$

2. $0.1\mathrm{\pi }-3\times {10}^{-5}\mathrm{\pi }$

3. $\frac{{10}^5}{3\mathrm{\pi }}-\frac{\mathrm{\pi }}{10}$

4. None of these

When does the voltage in a series LCR circuit lead the current? (Given that ${\mathrm{\omega }}_0=$resonant angular frequency)

1. $\mathrm{\omega }<{\mathrm{\omega }}_0$

2. $\mathrm{\omega }={\mathrm{\omega }}_0$

3. $\mathrm{\omega }>{\mathrm{\omega }}_0$

4. None of these

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

A 44 mH inductor is connected to a 220 V, 50 Hz ac supply. The RMS value of the current in the circuit is:

1. 1.0 A

2. 15 A

3. 15.92 A

4. 14.29 A