In the circuit shown in the figure below, if the potential at point \(\mathrm{A}\) is taken to be zero, the potential at point \(\mathrm{B}\) will be:

           

1. \(+1\) V
2. \(-1\) V
3. \(+2\) V
4. \(-2\) V

A thermocouple of negligible resistance produces an e.m.f. of 40 µV/ºC in the linear range of temperature. A galvanometer of resistance 10 ohm whose sensitivity is 1 µA/division, is employed with the thermocouple. The smallest value of temperature difference that can be detected by the system will be:
1. 0.25ºC
2. 0.5 ºC
3. 1ºC
4. 0.1ºC

The thermo e.m.f E in volts of a certain thermocouple is found to vary with temperature difference θ in ºC between the two junctions according to the relation
$E=30$ $\theta -\frac{{\theta }^2}{15}$ The neutral temperature for the thermo-couple will be:

1. 400ºC

2. 225ºC

3. 30ºC

4. 450ºC

A cell having an emf \(\varepsilon\) and internal resistance \(r\) is connected across a variable external resistance \(R\). As the resistance \(R\) is increased, the plot of potential difference \(V\) across \(R\) is given by:

1.		2.
3.		4.

The power dissipated in the circuit shown in the figure is \(30~\text{Watts}\). The value of \(R\) is:
    
1. \(15~\Omega\)
2. \(10~\Omega\)
3. \(30~\Omega\)
4. \(20~\Omega\)

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

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: