The peak value of an alternating emf \(E = E_{0}\sin\omega t\) is \(10\) volts and its frequency is \(50\) Hz. At a time \(t=\frac{1}{600}~\text{s},\) the instantaneous value of the emf will be:
1. | \(1\) volt | 2. | \(5 \sqrt{3}\) volts |
3. | \(5\) volts | 4. | \(10\) volts |
The time required for a \(50\) Hz sinusoidal alternating current to change its value from zero to the rms value will be:
1. \(1 . 5 \times 10^{- 2}~\text{s}\)
2. \(2 . 5 \times 10^{- 3}~\text{s}\)
3. \(10^{- 1}~\text{s}\)
4. \(10^{- 6}~\text{s}\)
A sinusoidal supply of frequency \(10\) Hz and rms voltage of \(12\) V is connected to a \(2.1~\mu\text{F}\) capacitor. What is the rms value of current?
1. \(5.5~\text{mA}\)
2. \(20~\text{mA}\)
3. \(26~\text{mA}\)
4. \(1.6~\text{mA}\)
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 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. | \(2\pi\) |
In a series LC circuit, if and is connected to a 100 V-50 Hz a.c. source, the impedance of the circuit is:
1.
2.
3.
4. None of these
When does the voltage in a series LCR circuit lead the current? (Given that resonant angular frequency)
1.
2.
3.
4. None of these
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) |