Q.1
Yokes with rectangular cross-section are used for
Q.2
The mcrease in heat dissipation by air blasts is due to increase in
Q.3
In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be
Q.4
In a D.C. machine the number of brush arms is _____ the number of poles.
Q.5
The operation of a D.C. machine with large air gap lengths is comparatively
Q.6
If an inductance is connected in one arm of bridge and resistances in the remaining three arms
Q.7
A sensitive galvanometer produces large deflection for a
Q.8
Which of the following are integrating instruments ?
Q.9
The use of _____ instruments is merely confined within laboratories as standardizing instruments.
Q.10
Which of the following meters are not used on D.C. circuits
Q.11
In a low power factor wattmeter the pressure coil is connected
Q.12
are used for construction of core of electromagnets.
Q.13
For measurements on high voltage capacitors, the suitable bridge is
Q.14
A moving-coil permanent-magnet instrument can be used as flux meter
Q.15
In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.
Q.16
is usually used for brush rockers
Q.17
In a Weston synchronoscope, the fixed coils are connected across
Q.18
The time taken by the machine to attain 0.632 of its final steady temperature rise is called
Q.19
With direct water cooling it is possible to have ratings of about
Q.20
In induction motors, the length of air gap in kept as small as mechanically possible is order to have
Q.21
Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ?
Q.22
In a Schering bridge the potential of the detector above earth potential is
Q.23
Induction type single phase energy meters measure electric energy in
Q.24
To measure radio frequency, the suitable frequency meter is
Q.25
The cold rolled grain oriented steel has ______ permeability in the direction of the grain orientation.
Q.26
D.C. windings are
Q.27
The design of electromagnets is based upon which of the following fundamental equations ?
Q.28
The length cf air gap to be provided in ______ is primarily determined by power factor consideration.
Q.29
Most common form of A.C. meters met with in every day domestic and industrial installations are
Q.30
Power transformers should be designed to have maximum efficiency
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