Measurement and Instrumentation

41. 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°

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42. 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

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43. 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

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44. In a meggar controlling torque is provided by

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

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

1. spring
2. gravity
3. eddy currents
4. all of the above

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46. In a Schering bridge the potential of the detector above earth potential is

1. a few volts only
2. 1 kV
3. 5 kV
4. 10 kV

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47. In a single phase power factor meter the phase difference between the currents in the two pressure coils is

1. exactly 0°
2. approximately 0°
3. exactly 90°
4. approximately 90°

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48. In a vibrating reed frequency meter the natural frequencies of two adjacent reeds have a difference of

1. 0.1 Hz
2. 0.25 Hz
3. 0.5 Hz
4. 1.5 Hz

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49. In a Weston frequency meter, the magnetic axes of the two fixed coils are

1. parallel
2. perpendicular
3. inclined at 60°
4. inclined at 120°

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50. In a Weston synchronoscope, the fixed coils are connected across

1. bus-bars
2. incoming alternator
3. a lamp
4. none of the above

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