The smallest change in a measured variable to which an instrument will respond is
Two bulbs marked 200 wtt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is
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Hysteresis losses in a d.c. machine are proportional to
Torque/ weight ratio of an instrument indicates
Series reactors are used to
What is the range for a 3(1/2)digit digital voltmeter ?
........ is the region of a transistor which has highest conductivity.
Two coils have self-inductances of 0.09 H and 0.01 H and mutual inductance of 0.015 H. The coefficient of coupling between coils is
Two resistances R1 and R2 give combined resistance of 4.5 ohms when in series and 1 ohm when in parallel. The resistance are
In a star-connected system without neutral grounding, zero-sequence currents are
Sensitivity of a voltmeter is given as
If one of the central springs of a Permanent Magnet Moving Coil ammeter is broken then when connected it will read
The positive sequence current of a transmission line is :
The teeth in the armature of a dc machine are sometimes skewed. This is done to reduce
When a line-to-ground fault occurs, the current in the faulted phase is 100 A. The zero-sequence current in this case will be :
Resistance across A and B in the circuit shown below is
In a CRT the highest positive potential is given to
the purpose of the synchronising control in a CRO is to
Power factor of an inductive circuit can be improved by connecting a capacitor to it in
In measurements made using a Q-meter impedance elements should preferably be connected in
Wagner Eearth devices in ac bridge circuits are used for
When the supply terminals of a dc shunt motor are interchanged
The current of a single-phase load drawn from a 3-phase system has:
The minimum number of wattmeter (s) required to measure 3-phase 3-wire balanced or unbalance power is
The voltage coil of a single phase house energy meter
Which one of the following methods decreases the error due to connections in a dynamometer type wattmeter ?
If the positive-, negative-and zero-sequence reactances of an element of a power system are 0.3, 0.3 and 0.8 pu respectively, then the element would be a
A separately excited dc generator is feeding a dc shunt motor. If the load torque on the motor is halved approximately
A manganin swamp resistance is connected in series with a moving coil ammeter consisting of a milliameeter and a suitable shunt in order of