Measuring Instruments MCQ

1. In a portable instrument, the controlling torque is provided by

  1. Spring
  2. Gravity
  3. Eddy currents
  4. Damping friction
Answer. a

2. Two meters X and Y require 40 mA and 50 mA for full-scale deflection. Which of the following is correct?

  1. X is more sensitive.
  2. Y is more sensitive.
  3. Both are equally sensitive.
  4. It is not possible to determine the relationship between the sensitivity of the meters from the given data.
Answer. c

3. Which type of support is required for a sensitive galvanometer?

  1. Pivot support
  2. Unilateral support
  3. Suspension support
  4. Pivot and unilateral support
Answer. c

4. A dynamo works on the principle of

  1. Supercharging
  2. Electromagnetic induction
  3. Alternating current
  4. Kirchoff’s law
Answer. b

5. Ideally, the damping torque should be

  1. Proportional to velocity of the moving system and operating current.
  2. Proportional to the velocity of the moving system but independent of operating current.
  3. Independent of the velocity of the moving system and proportional to the operating current.
  4. Independent of the velocity of the moving system and operating current.
Answer. b

6. Pick the odd one out

  1. Moving iron meter
  2. Moving coil meter
  3. Dynamometer wattmeter
  4. Watt-hour meter
Answer. d

7. Identify the instrument which has no controlling torque

  1. Electrostatic voltmeter
  2. Power factor meter
  3. Dynamometer type ammeter
  4. Wattmeter
Answer. b

8. An instrument gives maximum deflection for any amount of quantity passed through it. Which of the following pairs is present?

  1. Deflecting and controlling force
  2. Controlling and damping
  3. Deflecting and damping
  4. Deflecting, controlling and damping
Answer. c

9. The correct statement about electrodynamometer instrument amongst the following is

  1. Its scale is linear
  2. It measures only DC
  3. It is a transfer instrument
  4. Its sensitivity is lesser than M.I. type instruments
Answer. c

10. Damping torque in measuring instruments provided by fluid friction damping is mainly used

  1. Where low magnetic fields are produced
  2. Where high magnetic fields are produced
  3. Where deflecting torque is minimum
  4. Where permanent magnet produces the required deflecting torque.
Answer. c