Measurement and Instrumentation Multiple Choice Questions and Answers

11. For measuring current at high frequency we should use

1. moving iron instrument
2. electrostatic instrument
3. thermocouple instrument
4. none of the above

12. If an inductance is connected in one arm of bridge and resistances in the remaining three arms

1. the bridge can always be balanced
2. the bridge cannot be balanced
3. the bridge can be balanced if the resistances have some specific values

13. If an instrument has cramped scale for larger values, then it follows

1. square law
2. logarithmic law
3. uniform law
4. none of the above

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

1. 10°
2. 80°
3. 120°
4. 170°

15. In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be

1. unity
2. 0.5
3. 0.3
4. zero

16. In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was

1. unity
2. 0.8 lagging
3. 0.8 leading
4. zero

17. In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at

1. 0°
2. 60°
3. 90°
4. 120°

18. In a low power factor wattmeter the compensating coil is connected

1. in series with current coil
2. in parallel with current coil
3. in series with pressure coil
4. in parallel with pressure coil

19. In a low power factor wattmeter the pressure coil is connected

1. to the supply side of the current coil
2. to the load side of the current coil
3. in any of the two meters at connection
4. none of the above

20. In a meggar controlling torque is provided by

1. spring
2. gravity
3. coil
4. eddy current