A wire of a certain material is stretched slowly by ten percent, it's new resistance and specific resistance become, respectively:

1. 1.2 times, 1.1 times

2. 1.21 times, same

3. both remain the same

4. 1.1 times, 1.1 times

A cell can be balanced against 100 cm and 110 cm of potentiometer wire, respectively with and without being short-circuited through a resistance of 10 Ω. Its internal resistance is:

1.  1.0 Ω

2.  0.5 Ω

3.  2.0 Ω

4.  zero

The total power dissipated in watts in the circuit shown below is:

Three resistances \(\mathrm P\), \(\mathrm Q\), and \(\mathrm R\), each of \(2~\Omega\) and an unknown resistance \(\mathrm{S}\) form the four arms of a Wheatstone bridge circuit. When the resistance of \(6~\Omega\) is connected in parallel to \(\mathrm{S}\), the bridge gets balanced. What is the value of \(\mathrm{S}\)?
1. \(2~\Omega\)
2. \(3~\Omega\)
3. \(6~\Omega\)
4. \(1~\Omega\)

Two cells having the same emf, are connected in series through an external resistance R. Cells have internal resistance r₁ and r₂ respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is:

1. $r_1-r_2$

2. $\frac{r_1+r_2}{2}$

3. $\frac{r_1-r_2}{2}$

4. $r_1+r_2$

The power dissipated across the 8 Ω resistor in the circuit shown here is 2 W. The power dissipated in watts across the 3 Ω resistor is:

Kirchhoff’s first and second laws for electrical circuits are consequences of: