Simple Circuit

Q. In the circuit shown in figure, the voltmeter reading would be

1. Zero
2. 0.5 volt
3. 1 volt
4. 2 volt

Q. In an LCR circuit as shown below both switches are open initially. Now switch $S_1$ is closed, $S_2$ kept open. (q is charge on the capacitor and $\tau =RC$ is capacitive time constant). Which of the following statement is correct?

1. At $t=2\tau ,q=CV(1-e^{-2})$
2. Work done by the battery is half of the energy dissipated in the resistor
3. At $t=\tau ,q=\frac{CV}{2}$
4. At $t=\frac{\tau }{2},q=CV(1-e^{-1})$

Q. In an LCR circuit as shown below both switches are open initially. Now switch $S_1$ is closed, $S_2$ kept open. (q is charge on the capacitor and $\tau =RC$ is capacitive time constant). Which of the following statement is correct?

1. At $t=2\tau ,q=CV(1-e^{-2})$
2. At $t=\frac{\tau }{2},q=CV(1-e^{-1})$
3. At $t=\tau ,q=\frac{CV}{2}$
4. Work done by the battery is half of the energy dissipated in the resistor

Q. If in the given figure i = 0.25 amp, then the value R will be

1. $48\Omega$
2. $12\Omega$
3. $120\Omega$
4. $42\Omega$

Q. Two coaxial coils are very close to each other and their mutual inductance is $3\text{H}.$ If a current $i_1=2\sin 30t\text{A}$ is passing through the first coil, then find the peak value of induced emf in the second coil.

1. $180\text{V}$
2. $\frac{180}{\sqrt{2}}\text{V}$
3. $90\text{V}$
4. $0\text{V}$

Q. What is the direction of current flow in this circuit?

1. Clockwise
2. Anticlockwise
3. Into the plane of the circuit
4. Out of the plane of the circuit.

Q. Say switches $S_1,S_2$ and so on upto $S_6$ are closed, one after other in order (first $S_1$, then $S_2$) at regular intervals of $1\text{minute}$ starting from $t=0$. The switch $S_1$ is closed at $t=1\text{min}$. The graph of current versus time is best represented as

1. 
2. 
3. 
4. None of these

Q. A current of two amperes is flowing through a cell of e.m.f. 5 volts and internal resistance 0.5 ohm from negative to positive electrode. If the potential of negative electrode is 10V, the potential of positive electrode will be

1. 5 V
2. 14 V
3. 15 V
4. 16 V

Q. The $Si$ diode and the $Ge$ diode start conducting at $0.7\text{V}$ and $0.3\text{V}$ respectively, in the given circuit. If the $Ge$ diode connection be reversed. What will be the values of $V_0$ ​ and $I?$

1. $2.34\text{mA},12.7\text{V}$
2. $2.34\text{mA},11.7\text{V}$
3. $2.26\text{mA},11.3\text{V}$
4. $2.26\text{mA},11.7\text{V}$

Q. Two resistances $R_1$ and $R_2$ are joined as shown in the figure to two batteries of e.m.f. $E_1$and $E_2$. If $E_2$is short-circuited, the current through $R_1$ is

1. $\frac{E_1}{R_1}$
2. $\frac{E_2}{R_1}$
3. $\frac{E_2}{R_2}$
4. $\frac{E_1}{(R_2+R_1)}$

Q. The $Si$ diode and the $Ge$ diode start conducting at $0.7\text{V}$ and $0.3\text{V}$ respectively, in the given circuit. If the $Ge$ diode connection be reversed. What will be the values of $V_0$ ​ and $I?$

1. $2.34\text{mA},12.7\text{V}$
2. $2.26\text{mA},11.3\text{V}$
3. $2.26\text{mA},11.7\text{V}$
4. $2.34\text{mA},11.7\text{V}$

Q. If $24$ cells each of internal resistance $I$ $\Omega$ are to be connected in series and parallel combination to get the maximum power output across a load of $10$ $\Omega$. If $x$ represents the number of rows and $y$ represents the number of cells in each row. Which of the following relation between $x$ and $y$ is correct?

1. $y-x=23$
2. $y-x=10$
3. $y-x=23$
4. $y-x=5$

Q. In the given figure, a diode 'D' is connected to an external resistance $R=100\Omega$ and an emf of $3.5V$. If the barrier potential developed across the diode is $0.5V$, the current in the circuit will be

1. $35mA$
2. 
   $30mA$
3. 
   $40mA$
4. $20mA$

Q. Say switches $S_1,S_2$ and so on upto $S_6$ are closed, one after other in order (first $S_1$, then $S_2$) at regular intervals of $1\text{minute}$ starting from $t=0$. The switch $S_1$ is closed at $t=1\text{min}$. The graph of current versus time is best represented as

1. 
2. 
3. 
4. None of these