What is the value of the power factor for a parallel LC circuit at a frequency less than the resonance frequency?
1. Zero
2. 1
3. > 1
4.< 1
When an alternating voltage is given as \(E = (6 \sin\omega t - 2 \cos \omega t)\) volt, what is its rms value?
1. \(4 \sqrt 2 \) V
2. \(2 \sqrt 5\) V
3. \(2 \sqrt 3\) V
4. \(4\) V
An LC circuit contains an inductor (L=25 mH) and a capacitor (C=25 mF) with an initial charge of Q0. At what time will the circuit have an equal amount of electrical and magnetic energy?
4. All of these
In which of the following circuits can the power factor be zero?
1. LC circuit
2. LCR circuit
3. Purely resistive circuit
4. Both (1) & (2)
The circuit is in a steady state when the key is at position \(1\). If the switch is changed from position \(1\) to position \(2\), then the steady current in the circuit will be:
1. | \(E_o \over R\) | 2. | \(E_o \over 3R\) |
3. | \(E_o \over 2R\) | 4. | \(E_o \over 4R\) |
1. | \(2500\) W | 2. | \(250\) W |
3. | \(5000\) W | 4. | \(4000\) W |
In a box \(Z\) of unknown elements (\(L\) or \(R\) or any other combination), an ac voltage \(E = E_0 \sin(\omega t + \phi)\) is applied and the current in the circuit is found to be \(I = I_0 \sin\left(\omega t + \phi +\frac{\pi}{4}\right)\). The unknown elements in the box could be:
1. | Only the capacitor |
2. | Inductor and resistor both |
3. | Either capacitor, resistor, and an inductor or only capacitor and resistor |
4. | Only the resistor |
A capacitor of capacitance \(1~\mu\text{F}\) is charged to a potential of \(1\) V. It is connected in parallel to an inductor of inductance \(10^{-3}~\text{H}\).
What is the value of the maximum current that will flow in the circuit?
1. \(\sqrt{1000}~\text{mA}\)
2. \(1~\text{mA}\)
3. \(1~\mu\text{F}\)
4. \(1000~\text{mA}\)
1. | \(20\) W | 2. | \(30\) W |
3. | \(10\) W | 4. | \(40\) W |