1. A potentiometer can not be used to
- Measure emf of a cell
- Compare emf of two cells
- Measure unknown temperature
- Measure the internal resistance of a cell
2. For measuring an A.C. voltage by an A.C. potentiometer the supply for the potentiometer is taken from
- Same source as unknown voltage
- Different source other than unknown voltage
- A battery
- Source of supply does not matter
3. A standard cell of 1.0185 V is used with a slide wire potentiometer. The balance was obtained at 60 cm. When an unknown emf was connected, the balance was obtained at 82 cm. What is the magnitude of unknown emf?
- 1.39 V
- 0.75 V
- 13.9 V
- 7.45 V
4. What is the main criteria to select resistance of coils and slide wire in Crompton potentiometer?
- 14 coils and slide wire all having the same resistance
- 14 coils and slide wire but the resistance of slide wire is half of that of each coil
- 14 coils and slide wire all having the different resistance
- 14 coils out of which 7 coils have resistance which is twice that of the remaining 7 coils
5. What is the main purpose of the potentiometer as a device for?
- Comparing two voltages
- Comparing two currents
- Measuring a voltage
- Measuring a current
6. During the measurement of a low resistance using a potentiometer, the following readings were obtained:
Voltage drop across unknown resistance = 0.531 volt.
Voltage drop across a 0.1 ohm standard resistance connected in series with the unknown = 1.083 Volt. Value of the unknown resistor is
- 49.03 miliohm
- 108.3 milliohm
- 20.4 miliohm
- 53.1 miliohm
7. A potentiometer is used to measure the voltage between two points of a D.C. circuit, which is found to be 1.2 V. This is also measured by a voltmeter, which is found to be 0.9 V. The resistance of the voltmeter is 60 kΩ. The input resistance between two points.
- 60 kΩ
- 20 kΩ
- 45 kΩ
- 80 kΩ
8. Current in a circuit is measured using a simple slide wire. What will be the voltage drop per unit length if the standard cell is of emf 2.38 V balanced at length of 35 cm?
- 0.68 V/cm
- 0.068 V/cm
- 68 V/cm
- 6.8 V/cm
9. The standardization of AC potentiometer is done by using
- d.c. standard sources and transfer instruments
- a.c. standard voltage source directly
- a.c. standard sources and transfer instrument
- d.c. standard sources and d.c. galvanometer
10. Standardization of potentiometer is done in order that, they become
- Accurate and direct reading
- Accurate and precise
11. A potential divider is normally connected
- Outside the generator circuit towards the load circuit
- Within the generator circuit
- At a distance V/100 meters from the generator where V is the voltage to be measured in kV
- None of these
12. Which type of potentiometer consists of two separate potentiometer circuits enclosed in a common case?
- Gall tinsley AC potentiometer
- Drysdale tinsley AC potentiometer
- Cambell Larsen potentiometer
- Cromton potentiometer
13. Find the maximum value of excitation voltage for potentiometer, if there is a power dissipation of 6 W and maximum value resistance of the potentiometer is 500 Ω.
- 300 V
- 3000 V
- 54.77 V
- 90 V