Question 1

The objective of earthing or grounding is:

Accepted Answer

A)  to provide as low resistance possible to the ground
B)  to provide as high resistance possible to the ground
C)  to provide flow of positive, negative and zero sequence currents
D)  none of the above A

Question 2

Which of the following devices should be used for accurate measurement of low D.C. voltage ?

Accepted Answer

A)  small range moving coil voltmeter
B)  d.c. potentiometer
C)  small range thermocouple voltmeter
D)  none of the above B

Question 3

The electrical power to a meggar is provided by

Accepted Answer

A)  battery
B)  permanent magnet d.c. generator
C)  ac. generator
D)  any of the above B

Question 4

Anderson bridge is used to measure of:

Accepted Answer

A)  inductance
B)  capacitance
C)  time period
D)  resistance and capacitance

Question 5

Megger is an instrument used for the measurement of:

Accepted Answer

A)  high resistance and insulation resistance
B)  medium resistance
C)  low resistance
D)  leakage current

Question 6

In a meggar controlling torque is provided by

Accepted Answer

A)  spring
B)  gravity
C)  coil
D)  eddy current

Question 7

For measuring a very high resistance we should use

Accepted Answer

A)  kelvin\s double bridge
B)  wheat stone bridge
C)  meggar
D)  none of the above

Question 8

Generally grounding is provided for:

Accepted Answer

A)  only for the safety of the equipment
B)  only for the safety of the operating personnel
C)  both (a)  and (b) 
D)  none of the above

Question 9

The operating voltage of a meggar is about

Accepted Answer

A)  6 v
B)  12 v
C)  40 v
D)  100 v

Question 10

Ground resistance should be designed such that:

Accepted Answer

A)  grounding resistance should be as low as possible
B)  grounding resistance should be as high as possible
C)  grounding resistance should be always zero
D)  none of the above

Question 11

In an Anderson bridge, the unknown inductance is measured in terms of

Accepted Answer

A)  known inductance and resistance
B)  known capacitance and resistance
C)  known resistance
D)  known inductance

Question 12

Commonly used standard capacitor is

Accepted Answer

A)  spherical type
B)  concentric cylindrical type
C)  electrostatic type
D)  multilayer parallel plate type

Question 13

A potentiometer may be used for

Accepted Answer

A)  measurement of resistance
B)  measurement of current
C)  calibration of voltmeter
D)  all of the above

Question 14

The vale of resistance of an earthing electrode depends upon

Accepted Answer

A)  shape and material of the electrode
B)  depth to which electrode is driven into earth
C)  specific resistance of soil
D)  all of the above.

Question 15

If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is

Accepted Answer

A)  10°
B)  80°
C)  120°
D)  170°

Question 16

Maxwell's inductance capacitance bridge is used for measurement of inductance of:

Accepted Answer

A)  low q coils
B)  medium q coils
C)  low and medium q coils
D)  none of the above.

Question 17

Loss of charge method is used to measure:

Accepted Answer

A)  low r
B)  high r
C)  low l
D)  high l

Question 18

The most commonly used null deflector in a power frequency ac bridge is a

Accepted Answer

A)  vibration galvanometer
B)  d\arsanval galvanometer
C)  ballistic galvanometer
D)  tachometer

Question 19

It is required to measure the true open circuit e.m.f. of a battery. The best device is

Accepted Answer

A)  d.c. voltmeter
B)  ammeter and a known resistance
C)  d.c. potentiometer
D)  none of the above

Question 20

Standard resistor is made from

Accepted Answer

A)  platinum
B)  maganin
C)  silver
D)  nichrome

Exam 3: Electrical Measurement and Testing