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
The neutral temperature for the thermo-couple will be:
1. 400ºC
2. 225ºC
3. 30ºC
4. 450ºC
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
In the circuit shown in the figure below, if the potential at point \(A\) is taken to be zero, the potential at point \(B\) will be:
1. \(+1\) V
2. \(-1\) V
3. \(+2\) V
4. \(-2\) V
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:
1. | conservation of energy. |
2. | conservation of electric charge and energy respectively. |
3. | conservation of electric charge. |
4. | conservation of energy and electric charge respectively. |
The power dissipated across the \(8~\Omega\) resistor in the circuit shown here is \(2~\text{W}\). The power dissipated in watts across the \(3~\Omega\) resistor is:
1. | \(2.0\) | 2. | \(1.0\) |
3. | \(0.5\) | 4. | \(3.0\) |