A wire of resistance \(4~\Omega\) is stretched to twice its original length. The resistance of a stretched wire would be:

1.	\(4~\Omega\)	2.	\(8~\Omega\)
3.	\(16~\Omega\)	4.	\(2~\Omega\)

In the circuit shown cells, \(A\) and \(B\) have negligible resistance. For \(V_A =12 ~\text{V}\), \(R_1 = 500 ~\Omega \), and $\mathrm{}$\(R = 100 ~\Omega \) the galvanometer \((\text{G}) \) shows no deflection. The value of \(V_B\) is: 
     

1. \(4\) V
2. \(2\) V
3. \(12\) V
4. \(6\) V

If the voltage across a bulb rated \((220~\text{V}\text-100~\text{W})\) drops by \(2.5\%\) of its rated value, the percentage of the rated value by which the power would decrease is:
1. \(20\%\)
2. \(2.5\%\)
3. \(5\%\)
4. \(10\%\)

A ring is made of a wire having a resistance of \(R_0=12~\Omega.\). Find points \(\mathrm{A}\) and \(\mathrm{B}\), as shown in the figure, at which a current-carrying conductor should be connected so that the resistance \(R\) of the subcircuit between these points equals \(\frac{8}{3}~\Omega\)$\mathrm{?}$

If power dissipated in the \(9~\Omega\) resistor in the circuit shown is \(36\) W, the potential difference across the \(2~\Omega\) resistor will be:

            

A current of \(2~\text{A}\) flows through a \(2~\Omega\) resistor when connected across a battery. The same battery supplies a current of \(0.5~\text{A}\) when connected across a \(9~\Omega\) resistor. The internal resistance of the battery is:

A potentiometer circuit is set up as shown in the figure below. The potential gradient across the potentiometer wire is k volt/cm. Ammeter present in the circuit reads 1.0 A when the two-way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at lengths $l_1$ $cm$ and $l_2$ $cm$ respectively. The magnitudes of the resistors R and X in ohm, are then, respectively, equal to: 
   

1. $k(l_2-l_1)$ $and$ $k{l}_2$

2. $k{l}_1$ $and$ $k(l_2-l_1)$

3. $k(l_2-l_1)$ $and$ $k{l}_1$

4. $k{l}_1$ $and$ $k{l}_2$