Two cities are \(150~\text{km}\) apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is \(8\) volts and the average resistance per km is \(0.5~\text{ohm}\). The power loss in the wire is:
1. \(19.2~\text{W}\)
2. \(19.2~\text{kW}\)
3. \(19.2~\text{J}\)
4. \(12.2~\text{kW}\)
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. \(10\%\)
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. \(20~\Omega\)
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:
1. \(8\) V
2. \(10\) V
3. \(2\) V
4. \(4\) V
1. | is zero. |
2. | depends upon the choice of the two materials of the thermocouple. |
3. | is negative. |
4. | is positive. |
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
The neutral temperature for the thermo-couple will be:
1. 400ºC
2. 225ºC
3. 30ºC
4. 450ºC
A current of \(3~\text{A}\) flows through the \(2~\Omega\) resistor shown in the circuit. The power dissipated in the \(5~\Omega\) resistor is:
1. | \(4~\text{W}\) | 2. | \(2~\text{W}\) |
3. | \(1~\text{W}\) | 4. | \(5~\text{W}\) |
1. | \(6.3\) min | 2. | \(8.4\) min |
3. | \(12.6\) min | 4. | \(4.2\) min |
The total power dissipated in watts in the circuit shown below is:
1. | \(16\) W | 2. | \(40\) W |
3. | \(54\) W | 4. | \(4\) W |