The spring material used in a spring control device should have the following property.
1). Should be non-magnetic
2). Most be of low temperature co-efficient
3). Should have low specific resistance
4). All of the above
A Weston synchroscope is a
1). Moving coil instrument
2). Moving iron instrument
3). Dynamometer instrument
4). None of the above
In a moving coil instrument, the deflecting torque is proportional to
1). Current
2). Square of the current
3). Square root of the current
4). sine of the measurand
Least suitable transducer for static pressure measurement is-
1). Semi-conductor strain gauge
2). Variable capacitor for transducer
3). Metal wire strain gauge
4). Piezoelectric transducer
The current coil of a wattmeter is connected to the CT of R-phase. The potential coil is connected across Y and B phases. The wattmeter measures
1). Active power in R phase
2). Active power of Y phase
3). Reactive power of R phase
4). Power proportional to 3 phase power if the load is balanced