Q. No.A set of '\(n\)' equal resistors, of value '\(R\)' each, are connected in series to a battery of emf '\(E\)' and internal resistance '\(R\)'. The current drawn is \(I.\) Now, if '\(n\)' resistors are connected in parallel to the same battery, then the current drawn becomes \(10I.\) The value of '\(n\)' is:
1.
\(10\)
2.
\(11\)
3.
\(20\)
4.
\(9\)
1. \(\frac{R}{n}\)
2. \(n^{2}R\)
3. \(\frac{R}{n^{2}}\)
4. \(nR\)
A carbon resistor (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be:
1. Violet - Yellow - Orange - Silver
2. Yellow - Violet - Orange - Silver
3. Yellow - Green - Violet - Gold
4. Green - Orange - Violet - Gold
The figure shows a circuit that contains three identical resistors with resistance \(R = 9.0~\Omega\) each, two identical inductors with inductance \(L = 2.0~\text{mH}\) each, and an ideal battery with emf \(\varepsilon = 18~\text{V}\). The current \('i'\) through the battery just after the switch is closed will be:
1. \(0.2~\text{A}\)
2. \(2~\text{A}\)
3. \(4~\text{A}\)
4. \(2~\text{mA}\)
The potential difference \(V_{A}-V_{B}\) between the points \({A}\) and \({B}\) in the given figure is:
| 1. | \(-3~\text{V}\) | 2. | \(+3~\text{V}\) |
| 3. | \(+6~\text{V}\) | 4. | \(+9~\text{V}\) |
A filament bulb \((500~\text{W},100~\text{V})\) is to be used in a \(230~\text{V}\) main supply. When a resistance\(R\) is connected in series, the bulb works perfectly and consumes \(500~\text{W}.\) The value of \(R\) is:
| 1. | \(230~\Omega\) | 2. | \(46~\Omega\) |
| 3. | \(26~\Omega\) | 4. | \(13~\Omega\) |
| 1. | \(\dfrac{a^3R}{3b}\) | 2. | \(\dfrac{a^3R}{2b}\) |
| 3. | \(\dfrac{a^3R}{b}\) | 4. | \(\dfrac{a^3R}{6b}\) |
Two metal wires of identical dimensions are connected in series. If \(\sigma_1~\text{and}~\sigma_2\)
| 1. | \(\frac{2\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) | 2. | \(\frac{\sigma_1 +\sigma_2}{2\sigma_1\sigma_2}\) |
| 3. | \(\frac{\sigma_1 +\sigma_2}{\sigma_1\sigma_2}\) | 4. | \(\frac{\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) |
A circuit contains an ammeter, a battery of \(30~\text{V},\) and a resistance \(40.8~\Omega\) all connected in series. If the ammeter has a coil of resistance \(480~\Omega\) and a shunt of \(20~\Omega,\) then the reading in the ammeter will be:
1. \(0.5~\text{A}\)
2. \(0.02~\text{A}\)
3. \(2~\text{A}\)
4. \(1~\text{A}\)
\({A, B}~\text{and}~{C}\) are voltmeters of resistance \(R,\) \(1.5R\) and \(3R\) respectively as shown in the figure above. When some potential difference is applied between \({X}\) and \({Y},\) the voltmeter readings are \({V}_{A},\) \({V}_{B}\) and \({V}_{C}\) respectively. Then:
| 1. | \({V}_{A} ={V}_{B}={V}_{C}\) | 2. | \({V}_{A} \neq{V}_{B}={V}_{C}\) |
| 3. | \({V}_{A} ={V}_{B}\neq{V}_{C}\) | 4. | \({V}_{A} \ne{V}_{B}\ne{V}_{C}\) |
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