In a series ohmmeter, the resistance to be measured is connected in – series with the meter

Shunts are used in series ohmmeter to – spread out the range

Which of the following device should be used for accurate measurement of low D.C voltage – D.C potentiometer

It is required to measure the true open circuit e.m.f of a battery. The best device is – D.C potentiometer.

Bascially a potentiometer is a device for – comparing two voltages

In order to achieve high accuracy the slide wire of a potentiometer shiuld be – as long as possible.

Potentiometer is what type of instrument – comparison type

A phase shifting transformer is used in conjunction with – Drysdale potentiometer

most sensitive galvanometer is – spot ballistic galvanometer

The e.m.f. of a Weston standard cell can be measured by – potentiometer

The potentiometer wire should have – high specific resistance and low temperature coefficient

the cell used in potentiometer is – load assumulator

The multiplier and meter coil in a voltmeter are in – series

A moving iron instrument can be used for – both D.C and A.C

 The scale of a rectifier instrument is – linear

For measuring current at high frequency we should use – thermocouple instrument.

The resistance in the circuit of the moving coil of a dynamometer wattmeter should be – High

A dynamometer and wattmeter can be used for –  both DC and A.C

An induction wattmeter can be used for – DC only

The pressure coil of a wattmeter should be connected on the supply side of the circuit coil when load inpendence is high

In a low power factor wattmeter the compensating coil is connected in series with pressure coil

 in three-phase power measurement by two wattmeter method both the wattmeter had identical reading the power factor of the load was – Unity

 in a 3 phase power measurement by two wattmeter method the reading of one of the wattmeter was zero the power factor of the load must be 0.5

An ohmmeter is a – moving coil instrument

for measuring a very high resistance we should use – megger

 the electrical power to a mega is provided by permanent magnet – DC generator

in Meggar controlling torque is provided by – coil

 the operating voltage of megger is about 100 V

Murray loop test can be used for location of both the ground fault and the short circuit fault

 it is required to measure the true open circuit EMF of a battery the best device is – DC Potentiometer

a voltage of about 200 watt can be measured by – DC potentiometer in conjunction with volte ratio box

Wagner earthing device used used to eliminate errors due to electrostatic coupling

for measurement of mutual inductance we can use – Heaviside bridge

A power factor meter has one current circuit and two presure circuits.

 In a single phase power factor meter the phase difference between the currents in the two pressure coil is exactly 90 degree

In a dynamometer three phase power factor meter the Planes of the two moving coil are at – 120 degree

The power factor of a single phase load can be calculated if the instrument available are – one voltmeter one ammeter and one wattmeter

The desirable static characteristics of measuring systems are – accuracy sensitivity  and reproducibility

standard resistor is made from maganin

The rectifier instrument is not free from – frequency error

Alternating current is measured by – induction

Most sensitive Galvano meter is – spot ballistic galvanometer

Wattmeter cannot be designed on the principal of – moving iron instrument

The power of n-phase circuit can be measured by using a minimum of – (n-1) wattmeter elements.

A dynamometer type wattmeter responds to the – average value of active power.

Laboratoary wattmeter are – Electro dynometer type

The minimum number of wattmeter required to measure 3 phase 3 wire balanced or unbalanced power is – 2

The pressure coil of a dynometer type wattmeter is – highly resistive

The dynamometer wattmeter the moving coil is the – potential coil

A dynamometer type wattmeter responds to the average value of active power

The operating magnetic field in an electrodynamometer type of instrument has a flux density typically about 0.005wb/m2

In a two wattmeter method of measurement of 3 phase power of Balanced load if both the wattmeter indicates the same reading then the power factor of the load is – unity

For used in AC circuit potential coil circuit of electrodynamic wattmeter should be purely – resistive

Electrolytic metre is basically and – DC ampere hour metre

The household energy metre is integrating instrument

In a two wattmeter method of 3 phase power measurement of a balanced load one of the wattmeters read negative it may be concluded that the P.f of the lord is – less than 0.5

A two holes are drilled in the disc of diameter of energy metre to – eliminate creeping on no load

In two wattmeter method of power measurement wind power factor is unity the reading of Two wattmeter w1 and w2 are – W1 = W2

The internal resistance of ammeter should be – small

The resistance of ideal ammeter is – zero

The accurate ammeter must have a resistance of – very low value

Which of the following is likely to have the least resistance? – A ammeter

If an ammeter is connected in parallel to a circuit it is likely to be damaged due to excess – current

The internal resistance of an ammeter should be very low in order to have – minimum effect on the current in the circuit

The resistance of ideal voltmeter is –infinite

A voltmeter will read more accurate value if the resistance of voltmeter will be– greater

The accurate voltmeter must have a resistance of – very high value

Which of the following is likely to have the largest resistance? – A voltmeter

A voltmeter must have very high internal resistance so that – draw small amount of current

The internal resistance of a voltmeter should be very high in order to have :- minimum current through the meter

A milliammeter can be used as – voltmeter

The internal resistance of a voltmeter must be very high so that – minimum current passes through the meter

 

Share it
  • 3
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
    3
    Shares