During charging a capacitor, the variation of potential V of the capacitor with time t is shown as :

1. 

2. 

3. 

4. 

Two batteries, one of emf 18 volts and internal resistance 2Ω and the other of emf 12 volt and internal resistance 1Ω, are connected as shown. The voltmeter V will record a reading of.

1.  18 volt

2.  30 volt

3.  14 volt

4.  15 volt

In the circuit in the figure, if the potential at point A is taken to be zero, the potential at point B is :

1. -1V                                          2. +2V

3. -2V                                          4. +1V

A ring is made of a wire having a resistance 

${\mathrm{R}}_0=12\mathrm{\Omega }$. Find the points A and B, as shown

in the figure, at which a current carrying 

conductor should be connected so that the 

resistance R of the sub circuit between these

points is equal to 8/3$\mathrm{\Omega }$

1. $\frac{{\mathrm{l}}_1}{{\mathrm{l}}_2}=\frac{5}{8}$                   
2. $\frac{{\mathrm{l}}_1}{{\mathrm{l}}_2}=\frac{1}{3}$
3. $\frac{{\mathrm{l}}_1}{{\mathrm{l}}_2}=\frac{3}{8}$                   
4. $\frac{{\mathrm{l}}_1}{{\mathrm{l}}_2}=\frac{1}{2}$

A potentiometer wire of length L and a resistance r are connected in series with a battery of e.m.f. $E_o$ and a resistance r₁. An unknown e.m.f. is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by

1. $\frac{E_{o}rL}{\left(r_1\right)l}$

2. $\frac{E_{o}rl}{\left(r+r_1\right)L}$

3. E_ol/L

4. $\frac{E_{o}rL}{\left(r+r_1\right)l}$
 

The potential difference $\left({\mathrm{V}}_{\mathrm{A}}-{\mathrm{V}}_{\mathrm{B}}\right)$ between points A and B in the given figure is if the current is flowing from A to B:

1. - 3 V                   

2. +3 V

3. +6 V                 

4. +9 V

As in figure shown, if a capacitor C is charged by connecting it with resistance R, then energy  given by the battery will be 

1. $\frac{1}{2}C{V}^2$

2. More than $\frac{1}{2}C{V}^2$

3. Less than $\frac{1}{2}C{V}^2$

4. Zero

A light bulb, a capacitor and a battery are connected together as shown below with the switch S initially open. When the switch S is closed, which one of the following is true?

1. The bulb will light up for an instant when
    the capacitor starts charging.
2. The bulb will light up when
    the capacitor is fully charged.
3. The bulb will not light up at all.
4. The bulb will light up and go off at regular intervals.

Voltage drop across the terminals of a cell of EMF 2V is 1V when 2 A current is drawn from it. Internal resistance of the cell is?

1.  $2\mathrm{\Omega }$

2.  $1\mathrm{\Omega }$

3.  $0.5\mathrm{\Omega }$

4.  $0.25\mathrm{\Omega }$

When current flows in steady state in the wire whose area of cross-section decreases as shown. Which of the following is incorrect?

1.  Drift speed increases in the direction of current.

2.  Electric field decreases in the direction of current.

3.  Electric Potential decreases in the direction of current.

4.  Current density increases in the direction of current.