What is the equivalent resistance between A and B in the figure below if R = 3 $\Omega$?
                   
1. 9 $\Omega$

2. 12 $\Omega$

3. 15 $\Omega$

4. None of these

A torch bulb rated 4.5 W, 1.5 V is connected as shown in the figure below. The emf of the cell needed to make the bulb glow at full intensity is:

1. 4.5 V

2. 1.5 V

3. 2.67 V

4. 13.5 V

The figure below shows currents in a part of the electric circuit. The current \(i\) is:
    
1. \( 1.7 \mathrm{~A} \)
2. \( 3.7 \mathrm{~A} \)
3. \( 1.3 \mathrm{~A} \)
4. \( 1 \mathrm{~A}\)

In the following circuit, the battery $E_1$ has an e.m.f of 12 volts and zero internal resistance while the battery E has an e.m.f of 2 volts. If the galvanometer G reads zero, then the value of the resistance X in ohms is:

               
1. 10
2. 100
3. 500
4. 200

Figure (a) below shows a Wheatstone bridge in which P, Q R, S are fixed resistances, \(G\) is a galvanometer, and \(B\) is a battery. For this particular case, the galvanometer shows zero deflection. Now, only the positions of \(B\) and \(G\) are interchanged. as shown in figure (b). The new deflection of the galvanometer:

An electric heater consists of a nichrome coil and runs under \(220\) V, consuming \(1\) kW of power. Part of its coil burned out and it was reconnected after cutting off the burnt portion. The power it will consume now is:
 

The circuit shown contains three identical resistors, two ammeters X and Y, and a voltmeter Z. The internal resistance of the battery is negligible.
        
Which option shows the readings on the three meters?
(Assume the ammeters have negligible resistance, and negligible current flows through the voltmeter.)

A student has three \(6.0~\Omega\) resistors that can be connected together in any configuration. What are the maximum and minimum resistance that can be obtained by using one or more of these three resistors?
(Assume the connections between the resistors have negligible resistance, the temperature of the resistors is constant, and the resistors are used in a d.c. circuit and none of the resistors are short­circuited.)

Three resistors are connected to a \(20\) V battery with a constant supply. One of the resistors is a variable resistor. The resistance of the variable resistor is gradually increased from zero to \(5\) \(\Omega.\)
   
Which graph shows how the current from the battery varies with the resistance \((R)\) of the variable resistor?

1.		2.
3.		4.

A voltmeter of resistance \(660~\Omega\)$\mathrm{}$ reads the voltage of a very old cell to be \(1.32\) V while a potentiometer reads its voltage to be \(1.44\) V. The internal resistance of the cell is:
1. \(30~\Omega\)$\mathrm{}$ 
2. \(60~\Omega\)
3. \(6~\Omega\)
4. \(0.6~\Omega\)$\mathrm{}$