Voltmeter MCQ

1. A voltmeter must have very high internal resistance so that

  1. Accuracy is high
  2. Resolution is high
  3. Draws a small amount of current
  4. Creates high loading effect of the circuit
Answer. c

2. Which of the following is not correct?

  1. Voltmeter should have a very high resistance
  2. An ammeter should have a very low resistance
  3. A shunt should have a very low resistance
  4. An electronic voltmeter draws appreciable current from source
Answer. d

3. Sensitive low voltage electronic components are protected from

  1. Static charge
  2. Induction circuit
  3. Lightening
  4. All of these
Answer. d

4. In order to increase the range of a voltmeter

  1. A low resistance is connected in parallel
  2. A low resistance is connected in series
  3. A high resistance is connected in parallel
  4. A high resistance is connected in series
Answer. d

5. A galvanometer (G) measures upto 100 mA current. It is to be converted to a voltmeter to measure up to 100 volts. What is required to be done?

  1. Add 100 Ω resistance in series with G
  2. Add 1000 Ω resistance in series with G
  3. Add 1 Ω resistance in parallel with G
  4. Add 0.1 Ω resistance in parallel with G
Answer. b

6. The voltage of a circuit is measured by a voltmeter whose input impedance is low as compared to the output impedance of the circuit. The error caused will be due to

  1. Random error
  2. Loading effect
  3. Gross error
  4. System error
Answer. b

7.  The span of a zero centred voltmeter having a scale from -15 to +15 V is

  1. -30 V
  2. 30 V
  3. 0 V
  4. 15 V
Answer. b

8. The sensitivity of a voltmeter using 0 to 20 mA meter movement is

  1. 500 ohm/volt
  2. 100 ohm/volt
  3. 50 ohm/volt
  4. 20 ohm/volt
Answer. c

9. Series resistance  required to read o-250V with a moving coil instrument of internal resistance 2 Ω and full-scale deflection of 50 mA is

  1. 49998 ohm
  2. 4998 ohm
  3. 498 ohm
  4. 49.8 ohm
Answer. b

10. A voltmeter is used

  1. To measure current
  2. In series with the circuit
  3. In parallel with the circuit
  4. To measure coulombs
Answer. c

11. The sensitivity of a voltmeter using 0-5 mA meter movement is

  1. 200 ohm/V
  2. 150 ohm/V
  3. 100 ohm/V
  4. 50 ohm/V
Answer. a

12. What will happen if a voltmeter is connected like an ammeter in series of the load?

  1. The meter will burn out.
  2. The measurement will be too high.
  3. The same current will flow as would have been with ammeter in circuit.
  4. There will be almost no current in the circuit.
Answer. d

13. When a multiplier is added to an existing voltmeter for extending its range, its electromagnetic damping

  1. Remains unaffected
  2. Increases
  3. Decreases
  4. Changes by an amount depending on the controlling torque
Answer. c

14. What should be the properties and mode of connection of the shunts and multipliers used to increase the ranges of voltmeters and ammeters?

  1. Shunts-low resistance connected in parallel with ammeters
  2. Shunts-high resistance, connected in series with ammeters
  3. Multipliers-low resistance, connected in series with voltmeters
  4. Multipliers-high resistance, connected in parallel with voltmeters
Answer. a

15. The internal resistance of a voltmeter is 20,000 ohms. If this voltmeter is connected in series with a resistance and a 220 volt supply is connected across the combination, the voltmeter reads 200 volts. The value of the resistance is

  1. 200 ohm
  2. 4000 ohm
  3. 2000 ohm
  4. 20.000 ohm
Answer. c