The dependence of resistivity \((\rho)\) on the temperature \((T)\) of a semiconductor is, roughly, represented by:
1. | 2. | ||
3. | 4. |
Current through the \(2~\Omega\) resistance in the electrical network shown is:
1. | zero | 2. | \(1\) A |
3. | \(3\) A | 4. | \(5\) A |
A capacitor \(C\) is charged with the help of a resistance \(R\) as shown in the figure, Variation of \((V_{R}+V_{C})\) with time t is correctly shown in which of the options?
(\(V_{R}\) and \(V_{C}\) are instantaneous potential drops across \(R\) and \(C\) respectively).
1. | 2. | ||
3. | 4. |
Two batteries, one of emf \(18~\text{V}\) and internal resistance \(2~\Omega\) and the other of emf \(12\) V and internal resistance \(1~\Omega\), are connected as shown. Reading of the voltmeter is:
(if voltmeter is ideal)
1. \(14\) V
2. \(15\) V
3. \(18\) V
4. \(30\) V
A current of \(2\) A is to be sent through a resistor of \(5 ~\Omega.\) Number of cells required in series, if each has emf \(2\) V and internal resistance \(0.5~\Omega,\) are:
1. \(40\)
2. \(30\)
3. \(20\)
4. \(10\)
A \(50\) kW dc generator produces a potential difference of \(250\) V. If the resistance of the transmission line is \(1~\Omega\), what percentage of the original power is lost during transmission?
1. \(80\%\)
2. \(40\%\)
3. \(20\%\)
4. \(10\%\)
A potential divider is used to give outputs of \(2~\text{V}\) and \(3~\text{V}\) from a \(5~\text{V}\) source, as shown in the figure.
Which combination of resistances, from the ones given below, \(R_1, R_2, ~\text{and}~R_3\) give the correct voltages?1. | \({R}_1=1~\text{k} \Omega, {R}_2=1 ~\text{k} \Omega, {R}_3=2 ~\text{k} \Omega\) |
2. | \({R}_1=2 ~\text{k} \Omega, {R}_2=1~\text{k} \Omega, {R}_3=2~\text{k} \Omega\) |
3. | \({R}_1=1 ~\text{k} \Omega, {R}_2=2~ \text{k} \Omega, {R}_3=2~ \text{k} \Omega\) |
4. | \({R}_1=3~\text{k} \Omega, {R}_2=2~\text{k} \Omega, {R}_3=2~ \text{k} \Omega\) |
A potential difference is applied between \(A\) and \(B\). On closing the switch \(S\), readings of voltmeter(s):
1. | \({V_1}\) increases. |
2. | \({V_2}\) increases. |
3. | \({V_2}\) & \({V_3}\) both increases. |
4. | one of \(V_2\) & \({V_3}\) increases and \({V_1}\) decreases. |
What is the reading of the voltmeter of resistance \(1200~\Omega\) connected in the following circuit diagram?
1. | \(2.5\) V | 2. | \(5.0\) V |
3. | \(7.5\) V | 4. | \(40\) V |
In the given circuit diagram, \(3\) identical bulbs are connected. If bulb \(B_3\) get fused suddenly, how will the brightness of bulbs \(B_1\) and \(B_2\) change?
1. | Brightness of bulb \(B_1\) will increase whereas brightness of bulb \(B_2\) will decrease |
2. | Brightness of bulb \(B_2\) will increase whereas brightness of bulb \(B_1\) will decrease |
3. | Brightness of both bulbs \(B_1\) and \(B_2\) will increase |
4. | Brightness of bulb \(B_1\) will increase whereas brightness of bulb \(B_2\) will remain the same |