measurement instruments power energy measurement two wattmeter method ammeter voltmeter multimeter megger energy meter cro ct pt earth fault detection - Question Bank
1. In a DC circuit, a wattmeter measures:
2. Which instrument measures the rate of alternation of current or voltage?
3. A common method for detecting an earth fault involves monitoring the current flowing through the:
4. An energy meter measures energy in:
5. The 'X-gain' or 'Time/Div' control on a CRO adjusts the:
6. Which method is generally preferred for measuring power in a balanced three-phase circuit?
7. The 'Y-gain' or 'Volts/Div' control on a CRO adjusts the:
8. An ammeter can be converted into a voltmeter by connecting a ______ resistance in ______ with it.
9. A voltmeter can be converted into an ammeter by connecting a ______ resistance in ______ with it.
10. What is the primary purpose of using a CT and PT in power systems?
11. The CRO displays a graph of voltage versus ______.
12. In a three-phase system, if one wattmeter reads negative in the two-wattmeter method, it indicates that the power factor is:
13. Which device is used to measure insulation resistance of electrical machines and cables?
14. A series R-L circuit has a phase angle of 60 degrees. If a wattmeter measures 1000 W, what is the apparent power?
15. The braking magnet in an energy meter is usually made of:
16. In an induction type energy meter, the speed of the disc is proportional to the:
17. The most common instrument for measuring earth resistance is the:
18. Earth resistance measurement is critical for:
19. The standard secondary voltage rating for most PTs is:
20. A PT is essentially a ______ transformer.
21. The standard secondary current rating for most CTs is:
22. A CT is essentially a ______ transformer.
23. The 'Time Base' control on a CRO adjusts the:
24. Which instrument provides a visual representation of voltage signals over time?
25. A universal motor is a type of motor that can run on:
26. The internal resistance of an ideal ammeter should be:
27. The internal resistance of an ideal voltmeter should be:
28. If, in the two-wattmeter method for a balanced three-phase load, the power factor is unity, the readings of the two wattmeters are:
29. In a three-phase unbalanced load, the sum of the readings of two wattmeters in the two-wattmeter method gives:
30. A dynamometer type wattmeter is preferred for measuring power in AC circuits because it:
31. To compensate for the creeping effect in an energy meter, a small hole is often drilled in the:
32. The 'creeping' effect in an energy meter refers to:
33. Which type of energy meter uses a rotating disc driven by eddy currents induced by voltage and current coils?
34. Earth fault detection is crucial for:
35. The primary winding of a PT is connected in ______ with the high voltage line.
36. A Potential Transformer (PT) is used to:
37. The secondary winding of a CT should never be opened when the primary is energized because:
38. A Current Transformer (CT) is used to:
39. In a Cathode Ray Oscilloscope (CRO), the electron beam is deflected by:
40. Which instrument is used to display the waveform of an electrical signal and analyze its characteristics?
41. A wattmeter measures:
42. The unit of electrical energy is typically measured in:
43. A Megger typically uses a ______ generator to produce a high DC voltage for insulation testing.
44. What is the primary function of a Megger?
45. A multimeter is a versatile instrument that can measure:
46. A voltmeter is always connected in ______ with the circuit element across which the voltage is to be measured.
47. An ammeter is always connected in ______ with the circuit element whose current is to be measured.
48. In the two-wattmeter method for a balanced three-phase load, if the load is purely inductive, the reading of one wattmeter will be:
49. The two-wattmeter method is used to measure the total power in a:
50. Which type of meter is primarily used to measure the quantity of electrical energy consumed over a period of time?