41.
To avoid the effect of stray magnetic field in A.C. bridges we can use
A
magnetic screening
B
Wagner earthing device
C
wave filters
D
any of the above
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To avoid the effect of stray magnetic field in A.C. bridges we can use
magnetic screening
Wagner earthing device
wave filters
any of the above
The use of...............instruments is merely confined within laboratories as stand¬ardizing instruments
absolute
indicating
recording
integrating
The two pressure coils of a single phase power factor meter have
the same dimensions and the same number of turns
the same dimension but different number of turns
the same number of turns but different dimensions
none of the above
The switch board instruments
should be mounted in vertical position
should be mounted in horizontal position
either a or b
neither a nor b
The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a
single-phase winding
two-phase winding
three-phase winding
any of the above
The spring material used in a spring control device should have the following property.
Should be non-magnetic
Most be of low temperature co-efficient
Should have low specific resistance
All of the above
The scale of a rectifier instrument is
linear
non-linear
either a or b
neither a nor b
The resistance in the circuit of the moving coil of a dynamometer wattmeter should be
almost zero
low
high
none of the above
The rectifier instrument is not free from
temperature error
wave shape error
frequency error
all of the above
The ratio of maximum displacement deviation to full scale deviation of the instrument is called
static sensitivity
dynamic deviation
linearity
precision or accuracy
The principle on which vector voltmeter is based is
that it works on the principle of complex variation
that it measures the response of linear ramp voltage
same as digital meter
that it measures the amplitude of a single at two points and at the same time measures their phase difference
The pressure coil of a wattmeter should be connected on the supply side of the current coil when
load impedance is high
load impedance is low
supply voltage is low
none of the above
The power of a n-phase circuit can be measured by using a minimum of
(n - 1) wattmeter elements
n wattmeter elements
(n + 1) wattmeter elements
2n wattmeter elements
The power factor of a single phase load can be calculated if the instruments available are
one voltmeter and one ammeter
one voltmeter, one ammetqr and one wattmeter
one voltmeter, one ammeter and one energy meter
any of the above
The pointer of an indicating instrument should be
very light
very heavy
either a or b
neither a nor b
The operating voltage of a meggar is about
6 V
12 V
40 V
100 V
The multiplier and the meter coil in a voltmeter are in
series
parallel
series-parallel
none of the above
The household energy meter is
an indicating instrument
a recording instrument
an integrating instrument
none of the above
The gravity controlled instrument has crowded scale because current is proportional to
balancing weight
deflection angle
sine of deflection angle
The function of shunt in an ammeter is to
by pass the current
increase the sensitivity of the ammeter
increase the resistance of ammeter
none of the above