An AC source rated \(100~\text{V}\) (rms) supplies a current of \(10~\text{A}\) (rms) to a circuit. The average power delivered by the source:
(a) | must be \(1000~\text{W}\). |
(b) | may be \(1000~\text{W}\). |
(c) | may be greater than \(1000~\text{W}\). |
(d) | may be less than \(1000~\text{W}\). |
1. | (a) only |
2. | (b), (c) |
3. | (b), (d) |
4. | (a), (d) |
An AC source is rated \(220~\mathrm{V}\), \(50~\mathrm{Hz}\). The average voltage is calculated in a time interval of \(0.01~\mathrm{s}\). It,
1. | must be zero |
2. | may be zero |
3. | is never zero |
4. | \(220\sqrt{2}\) V | is
1. | \(1 / \sqrt{2}\) times the rms value of the AC source. |
2. | the value of voltage supplied to the circuit. |
3. | the rms value of the AC source. |
4. | \(\sqrt{2}\) times the rms value of the AC source. |
1. | \(\nu=100 ~\text{Hz} ; ~\nu_0=\dfrac{100}{\pi} ~\text{Hz}\) |
2. | \(\nu_0=\nu=50~\text{Hz}\) |
3. | \(\nu_0=\nu=\dfrac{50}{\pi} ~\text{Hz}\) |
4. | \(\nu_{0}=\dfrac{50}{\pi}~ \text{Hz}, \nu=50 ~\text{Hz}\) |
An AC source given by \(V=V_m\sin\omega t\) is connected to a pure inductor \(L\) in a circuit and \(I_m\) is the peak value of the AC current. The instantaneous power supplied to the inductor is:
1. \(\dfrac{V_mI_m}{2}\mathrm{sin}(2\omega t)\)
2. \(-\dfrac{V_mI_m}{2}\mathrm{sin}(2\omega t)\)
3. \({V_mI_m}\mathrm{sin}^{2}(\omega t)\)
4. \(-{V_mI_m}\mathrm{sin}^{2}(\omega t)\)
1. | \(100~\Omega.\) | the impedance in the circuit is
2. | \(200~\Omega.\) | the resistance in the circuit is
3. | \(484\) W. | the power dissipated is
4. | all the above are true. |
1. | \(\frac{\omega L}{R}\) | depends on the ratio
2. | \(\sqrt{(\omega L)^2+R^2}\) | depends on the quantity
3. | \(L\) and \(R,\) but not on \(\omega\) | depends on
4. | is independent of \(L,R,\omega\) |