Q. No.| 1. | \(60\) Hz and \(240\) V |
| 2. | \(19\) Hz and \(120\) V |
| 3. | \(19\) Hz and \(170\) V |
| 4. | \(754\) Hz and \(70\) V |
1. \( \frac{1}{\sqrt{2}}\left(i_1+i_2\right) \)
2. \( \frac{1}{\sqrt{2}}\left(i_i+i_2\right)^2 \)
3. \( \frac{1}{\sqrt{2}}\left(i_1^2+i_2^2\right)^{1 / 2} \)
4. \( \frac{1}{2}\left(i_1^2+i_2^2\right)^{1 / 2}\)
The peak value of an alternating emf; \(E = E_{0}\sin\omega t\) is \(10~\text V\) and its frequency is \(50~\text{Hz}.\) At a time \(t=\dfrac{1}{600}~\text{s},\) the instantaneous value of the emf will be:
1. \(1~\text V\)
2. \(5\sqrt 3~\text V\)
3. \(5~\text V\)
4. \(10~\text V\)
The variation of the instantaneous current \((I)\) and the instantaneous emf \((E)\) in a circuit are shown in the figure. Which of the following statements is correct?
| 1. | The voltage lags behind the current by \(\frac{\pi}{2}\). |
| 2. | The voltage leads the current by \(\frac{\pi}{2}\). |
| 3. | The voltage and the current are in phase. |
| 4. | The voltage leads the current by \(\pi\). |
When an alternating voltage is given as; \(E = (6 \sin\omega t - 2 \cos \omega t)~\text V,\) what is its RMS value?
1. \(4 \sqrt 2 ~\text V\)
2. \(2 \sqrt 5 ~\text V\)
3. \(2 \sqrt 3 ~\text V\)
4. \(4 ~\text V\)
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. \(10^{- 6}~\text{s}\)
| 1. | \(\dfrac{V_{0}}{\sqrt{3}}\) | 2. | \(V_{0}\) |
| 3. | \(\dfrac{V_{0}}{\sqrt{2}}\) | 4. | \(\dfrac{V_{0}}{2}\) |
Hence:
| 1. | The voltage leads the current by \(30^{\circ}\). |
| 2. | The current leads the voltage by \(30^{\circ}\). |
| 3. | The current leads the voltage by \(60^{\circ}\). |
| 4. | The voltage leads the current by \(60^{\circ}\). |
The output current versus time curve of a rectifier is shown in the figure. The average value of the output current in this case will be:
1. \(0\)
2. \(\dfrac{I_0}{2}\)
3. \(\dfrac{2I_0 }{ \pi}\)
4. \(I_0\)
| 1. | \(\frac{1}{100}~\text{sec}\) | 2. | \(\frac{1}{200}~\text{sec}\) |
| 3. | \(\frac{1}{300}~\text{sec}\) | 4. | \(\frac{1}{400}~\text{sec}\) |
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