Measurement MCQs Part-6

Measurement MCQs

1. The condition for a resistor to have the same value of resistance at medium frequencies as with d.c. is ________.

a. CR² = ωL

b. CR² = 2 L

c. CR² = L

d. CR² = 2 ωL

2. A 100 ohm resistor has a time constant of 30 ns. What is the value of the capacitor to be connected in parallel with the resistor to make its phase angle equal to zero?

a. 300 pF

b. 30 nF

c. 300 nF

d. 30 pF

3. The resistance of an earthing electrode depends upon_______.

a. Specific resistance of soil

b. depth to which electrode is driven into earth

c. Shape and material of electrode

d. All of the above

4. Which of the following method is not used for the measurement of resistance less than one ohm?

a. Potentiometer method

b. Voltmeter-ammeter method

c. ohm-meter method

d. Both (b) and (c)

5. Which of the following is not true regarding a potentiometer used in measurement of an unknown voltage source?

a. It can be used to determine current simply by measuring the voltage produced by the unknown current passing through a known standard resistance

b. Since no current flows, power consumed in the potentiometer circuit is zero

c. Accuracy is very low

d. It is the standard for the calibration of voltmeters and ammeters

6. The instrument normally used to check the insulation resistance is__________.

a. Tong-tester

b. Megger

c. Multimeter

d. Ohm-meter

7. The absolute measurement of resistance is done by_______.

a. Ohm's law 

b. Rayleigh

c. Lorenz

d. Bridge method

8. A meggar usually a______.

a. Moving coil type instrument

b. Electrostatic type instrument

c. Hot-wire type instrument

d. Moving iron  type instrument

9. A shunt type ohmmeter is not suitable for high resistance measurement because_______.

a. A very low resistance of the meter would short the high unknown resistance

b. Full scale value of meter may be exceeded

c. Battery cannot supply the necessary current for proper meter detection 

d. Scale is highly cramped for high resistance values

10. The accuracy of kelvin's double bridge for the measurement of low resistance is high because the bridge______.

a. Uses null indicating galvanometer

b. Uses a low resistance link between standard and test resistances

c. Has medium value resistance in the ratio arms

d. Use two pairs of resistance arms

11. A bridge circuit works at a frequency of 2.99 kHz. Which detector can be used for detecting the null conditions in the bridge?

a. Vibration galvanometer, headphones and tunable amplifiers

b. Headphones and tunable amplifiers

c. Vibration galvanometer and headphones

d. Vibration galvanometer and tunable amplifiers

12. Inductance comparison bridges uses______.

a. One 'C'

b. One 'L'

c. One 'L' and One 'C'

d. None of the above

13. In measurement of resistance by "Carey Foster bridge" no error is introduced due to_______.

a. Contact resistance

b. Thermoelectric emfs

c. Connecting leads

d. All of the above

14. An ac bridge uses a detector in the form of________.

a. Wattmeter

b. Headphones

c. Voltmeter

d. Ammeter

15. Maxwell's bridge is used to measure Q-factor in the range________.

a. 75-100

b. 30-50

c. 1-10

d. 50-75