21.
A direct current can be measured by
A
none of the above
B
a D.C. potentiometer directly
C
a D.C. potentiometer in conjunction with a standard resistance
D
a D.C. potentiometer in conjunction with a volt ratio box
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108 practice sets · Page 2 of 6
A direct current can be measured by
none of the above
a D.C. potentiometer directly
a D.C. potentiometer in conjunction with a standard resistance
a D.C. potentiometer in conjunction with a volt ratio box
.............instruments are those which measure the total quantity of electricity delivered in a particular time.
Integrating
Absolute
Indicating
Recording
Which of the following properties a damping oil must possess ?
All of the above
Must be a good insulator
Should be non-evaporating
Should not have corrosive action upon the metal of the vane
Which of the following meters are not used on D.C. circuits
None of the above
Mercury motor meters
Commutator motor meters
Induction meters
Which of the following is measured by using a vector voltmeter ?
All of the above
Amplifier gain and phase shift
Filler transfer functions
Complex insersion loss
Which of the following is an essential part of a motor meter ?
All of the above
An operating torque system
A braking device
Revolution registering device
Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?
Integrating instruments
Absolute instruments
Indicating instruments
Recording instruments
Which of the following essential features is possessed by an indicating instrument ?
All of the above
Deflecting device
Controlling device
Damping device
Which of the following devices should be used for accurate measurement of low D.C. voltage ?
None of the above
Small range moving coil voltmeter
D.C. potentiometer
Small range thermocouple voltmeter
Which of the following devices may be used for extending the range of instruments ?
All of the above
Shunts
Multipliers
Current transformers
Which of the following are integrating instruments ?
Ampere-hour and watt-hour meters
Ammeters
Voltmeters
Wattmeters
When a capacitor was connected to the terminal of ohmmeter, the pointer indicated a low resistance initially and then slowly came to infinity position. This shows that capacitor is
short-circuited
all right
faulty
Wattmeter cannot be designed on the principle of
electrodynamic instrument
electrostatic instrument
thermocouple instrument
moving iron instrument
Wagner earthing device is used to eliminate errors due to
electrostatic coupling
electromagnetic coupling
both a and b
none of the above
Volt box is a component to
extend voltage range
measure voltage
compare voltage in a box
none of the above
Various adjustments in an energy meter include
light load or friction
lag and creep
overload and voltage compensation
temperature compensation
Two holes in the disc of energymeter are drilled at the opposite sides of the spindle to
improve its ventilation
eliminate creeping at no load
increase its deflecting torque
increase its braking tcrque
To measure radio frequency, the suitable frequency meter is
Weston frequency meter
reed vibrator frequency meter
hetrodyne frequency meter
electrical resonance frequency meter
To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supplyfor the potentiometer in taken
from a source which is not the same as the unknown voltage
from a battery
from the same source as the unknown voltage
To measure a resistance with the help of a potentiometer it is
necessary to standardise the potentiometer
not necessary to standardise the potentiometer
necessary to use a volt ratio box in conjunction with the potentiometer
none of the above