GATE EE

Electrical and Electronics Measurement

Measurement of Energy and Power

Previous Years Questions

## Marks 1

Two wattmeter method is used for measurement of power in a balanced three-phase load
supplied from a balanced three-phase system. If one of the wattme...

A 3-phase balanced load which has a power factor of 0.707 is connected to a balanced supply. The power consumed by the load is 5 kW. The power is meas...

An $$LPF$$ wattmeter of power factor $$0.2$$ is having three voltage settings $$300V,$$ $$150V$$ and $$75V,$$ and two current settings $$5 A$$ and $$1...

While measuring power of a three-phase balanced load by the two-wattmeter method, the readings are $$100$$ $$W$$ and $$250$$ $$W$$. The power factor o...

Power consumed by a balanced $$3$$-phase, $$3$$-wire load is measured by the two wattmeter method. The first wattmeter reads twice that of the second....

For the circuit shown in the figure, the voltage and current expressions are
$$v\left( t \right) = {E_1}\sin \left( {\omega t} \right) + {E_3}\sin \l...

Consider the following statement:
(i) The compensating coil of a low power factor wattmeter compensates the effect of the impedance of the current coi...

A wattmeter is connected as shown in the fig. the wattmeter reads
...

A sampling wattmeter (that computes power from simultaneously sampled values of voltage and current) is used to measure the average power of a load. T...

The circuit in fig is used to measure the power consumed by the load. The current coil and the voltage coil of the watt meter have $$0.02$$ $$\Omega $...

The line to line input voltage to the $$3$$ phase, $$50$$ Hz, ac circuit shown in fig is $$100$$ $$V$$ $$r.m.s$$ Assuming that the phase sequence is ...

The minimum number of wattmeter(s) required to measure 3 $$-$$ phase, 3 $$-$$ wire balanced or unbalanced power is

Electro dynamic type watt meters have large errors while measuring power in a.c circuits at low power factor conditions, since the voltage across and ...

A dynamometer type wattmeter responds to the

The moving coil in a dynamometer wattmeter is connected

A water boiler at home is switched on to the $$A.C$$ mains supplying power at $$230$$ $$V/50$$ $$Hz.$$ The frequency of instantaneous power consumed b...

VRN, VYN and VBN are the instantaneous line to neutral voltages and iR, iY and iB are instantaneous line currents in a balanced three-phase circuit, ...

## Marks 2

The load shown in the figure is supplied by a $$400$$ $$V$$ (line-to-line) $$3$$-phase source ($$RYB$$ sequence). The load is balanced and inductive, ...

The coils of a wattmeter have resistances $$0.01$$ $$\Omega $$ and $$1000$$ $$\Omega $$; their inductances may be neglected. The wattmeter is connecte...

The figure shows a three phase delta connected load supplied from a $$400V,$$ $$50Hz,$$ $$3\phi $$ balanced source. The pressure coil and current coil...

A $$3$$ $$V$$ $$dc$$ supply with an internal resistance of $$2\,\,\Omega $$ supplies a passive non-linear resistance characterized by the relation $${...

An energy meter connected to an immersion heater (resistive) operating on an $$AC$$ $$230V,$$ $$50$$ $$Hz,$$ $$AC$$ single phase source reads $$2.3$$ ...

Two wattmeter's, which are connected to measure the total power on a three-phase system supplying a balanced load, read $$10.5$$ $$kW$$ and $$–2.5$$ $...

A single-phase load is connected between $$R$$ and $$Y$$ terminals of a $$415$$ $$V,$$ symmetrical, $$3$$-phase, $$4$$-wire system with phase sequence...

A dc A-h meter is rated for 15 A, 250V. The meter constant is 14.4 A-sec/rev. The meter constant at rated voltage may be expressed as

The voltage-flux adjustment of a certain $$1$$-phase $$220$$ $$V$$ induction watt-hour meter is altered so that the phase angle between the applied vo...

A wattmeter reads $$400$$ $$W$$ when its current coil is connected in the $$R$$ phase and its pressure coil is connected between this phase and the ne...

The two wattmeter method is used to measure active power on a three phase, three wire system. If the phase voltage is unbalanced, then the power readi...

The voltage phasor of a circuit is $$10\angle {15^ \circ }V$$ and the current phasor is $$2\angle - {45^ \circ }A.$$ The active and the reactive powe...

For the circuit shown in Fig, the wattmeter reading will be .... W and the power dissipted in the load is ......W
...

## Marks 5

A $$3$$ - $$\phi $$ load operates with balanced voltages applied to its terminals, and draws balanced currents. The potential coil of a moving coil wa...

A symmetrical $$400V,$$ $$3$$-$$\phi $$ supply is connected to the network shown in fig. The phase sequence is $$RYB.$$ Find the reading on the wattme...