Which of the following essential features is possessed by an indicating instrument ?
(A) Deflecting device
(B) Controlling device
(C) Damping device
(D) All of the above
Which of the following properties a damping oil must possess ?
(A) Must be a good insulator
(B) Should be non-evaporating
(C) Should not have corrosive action upon the metal of the vane
(D) The viscosity of the oil should not change with the temperature
(D) All of the above
For handling greater currents induction wattmeters are used in conjunction with______________?
(A) potential transformers
(B) current transformers
(C) power transformers
(D) either of the above
(D) none of the above
is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another_______________?
(A) Tangent galvanometer
(B) Meggar
(C) Current transformer
(D) None of the above
Induction type single phase energy meters measure electric energy in_______________?
(A) kW
(B) Wh
(C) kWh
(D) VAR
(D) None of the above
A moving-coil permanent-magnet instrument can be used as flux-meter_____________?
(A) by using a low resistance shunt
(B) by using a high series resistance
(C) by eliminating the control springs
(D) by making control springs of large moment of inertia
Most common form of A.C. meters met with in every day domestic and industrial installations are______________?
(A) mercury motor meters
(B) commutator motor meters
(C) induction type single phase energy meters
(D) all of the above
__________ instruments are those which measure the total quantity of electricity delivered in a particular time ?
(A) Absolute
(B) Indicating
(C) Recording
(D) Integrating
Resistances can be measured with the help of_______________?
(A) wattmeters
(B) voltmeters
(C) ammeters
(D) ohmmeters and resistance bridges
(D) all of the above