# MCQ on Electrical Measuring Instruments with Answers

### 1. Which bridge is used to determine frequency?

(a) Anderson bridge.
(b) De Sauty bridge.
(c) Wien bridge.
(d) Campbell bridge.

### 2. Which one of the following is a frequency sensitive bridge?

(a) De-Sauty bridge.
(b) Schering bridge.
(c) Wien’s bridge.
(d) Maxwell’s bridge.

### 3. Which of the following bridges can be used to construct a harmonic distortion analyzer ?

1. Maxwell bridge.
2. Hay bridge.
3. Schering bridge.
4. Wien bridge.

Select the correct answer using the code given below Code :
(a) Only 1 and 2
(b) Only 2 and 3.
(c) Only 3 and 4.
(d) Only 4.

### 4. Consider the following statements in respect of a Wien bridge.

1. It is suitable for measurement of capacitance.
2. It is not affected by harmonics present in the applied voltage.
3. It is suitable for measurement of frequency.

Which of these statement are correct ?
(a) 1, 2 and 3.
(b) 1 and 2.
(c) 2 and 3.
(d) 1 and 3.

### 5. In Wien bridge

(a) balanced conditions are independent of frequency.
(b) balanced conditions are dependent on frequency.
(c) capacitance is measured in terms of standard inductance.
(d) frequency is measured in terms of resistance and capacitance values.

### 6. Schering bridge can be used to measure which one of the following?

(a) Q of a coil.
(b) Inductance and its Q-value.
(c) Very small resistance.
(d) Capacitance and its power factor.

### 7. Schering bridge is suitable for measurement of

(a) Q of a coil.
(b) L of a coil.
(c) capacitance.
(d) dissipation factor.

### 8. Dissipation factor, tan δ, of a capacitor measured by which bridge?

(a) Anderson bridge.
(b) Hay bridge.
(c) Schering bridge.
(d) Wien bridge.

### 9. The dielectric loss of a capacitor can be measured by which one of the following?

(a) Wien bridge.
(c) Schering bridge.
(b) Owen bridge.
(d) Maxwell bridge.

### 10. The imperfect capacitance which is shunted by a resistance can be measured by which one of the following ?

(a) Carey Foster bridge.
(b) Owen bridge
(c) Schering bridge.
(d) Wien bridge.

### 11. Which one of the following bridges is used for measurement of dielectric loss and power factor of a capacitor ?

(a) Maxwell’s bridge.
(b) Anderson bridge.
(c) De Sanity’s bridge.
(d) Schering bridge.

### 12. Which of the following is used to measure the leakage resistance of a capacitor ?

(a) Megger.
(b) Schering bridge.
(c) Potentiometer.
(d) Loss of charge method.

### 13. The capacitance and loss angle of a given capacitor specimen are best measured by

(a) Wheatstone bridge.
(b) Maxwell bridge.
(c) Anderson bridge.
(d) Schering bridge.

### 14. AC bridges

(a) have leakage error and eddy current errors only.
(b) have residual errors, frequency errors and waveform errors only.
(c) both (a) and (b).
(d) are free from errors.

### 15. Wagner Earth devices in ac bridge circuits are used for

(a) Shielding all the bridge elements from external magnetic field.
(b) Eliminating the effect of stray capacitance.
(c) Minimizing the effect of intercomponent capacitance.
(d) Eliminating all the node to earth capacitances.

### 16. What should be the main characteristic(s) of the null detector in a bridge measurement ?

1. Accuracy.
2. Precision.
3. Sensitivity.
4. Resolution.

Select the correct answer using the code given below : Code :
(a) Only 1 and 2.
(b) Only 2 and 3.
(c) Only 3 and 4.
(d) Only 3.

### 17. Which of the following factors decide the accuracy in a bridge measurement ?

1. Accuracy of the null indicator.
2. Accuracy of the bridge components.
3. Sensitivity of the null indicator.
4. Applied voltage to the bridge system.

Select the correct answer using the code given below
(a) 1 and 2.
(b) 2 and 3.
(c) 3 and 4.
(d) 1 and 3.

### 18. A bridge circuit works at a frequency of 2 kHz. Which detector can be used for detecting the null conditions in the bridge ?

(a) Vibration galvanometer and head phones.
(b) Head phones and tunable amplifiers.
(c) Vibration galvanometer and tunable amplifiers.
(d) Vibration galvanometer, head phones and tunable amplifiers.

### 19. Vibration galvanometers, tunable amplifiers and head phones are used in

(a) dc bridges.
(b) ac bridges.
(c) both dc and ac bridges.
(d) Kelvin double bridge.

### 20. In the loop tests performed for localizing the earth fault in cables the fault resistance

(a) affects the balance conditions.
(b) affects the sensitivity of the bridge.
(c) affects the value of cable resistance.
(d) all of the above.