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A circle is seen on the screen of a CRO when two time varying signals of same frequency and
same magnitude are applied to X and Y plates of CRO. The relative phase difference is

A) 360° 8) 90൦ C) 180° D) 45°
Calibration of a voltmeter is done through

A) A hertz meter B) An ampere hour meter
C) Asignal generator D) A potentiometer

What would be the sensitivity of an ammeter which requires change of 2A in its coil to
produce a change in deflection of the pointer by 6 mm ?

A) 0.3 mm/A B) 0.3 A/mm
@) 3 4 D) 3 A/mm

A 0 to 300 V voltmeter has guaranteed accuracy of 1% full scale reading. The voltage
measured by the instrument is 96 V. The percent limiting error is

A) 0.32% B) 3.13% C) 1.81% D) 0.81%
If an instrument has cramped scale for larger values, then it follows

A) Uniform law B) Square law

C) Logarithmic law D) None of the above

The power of a 1-phase 3.3 kV load drawing a current of 30 A is required to be measured
by means of a wattmeter having potential terminals marked as 110 V and current terminals
as 6 A. What is the transformation ratio of the CT ?

A) 5A 8) 0.22 C) 18.33 A 0) 0.54

If an alternating voltage source is connected to a power transformer, its no load current
would be

A) Sinusoidal and lagging the voltage by 90°
B) Sinusoidal and lagging the voltage by less than 90°
C) Sinusoidal and leading the voltage by 90°
D) Sinusoidal and leading the voltage by less than 90°

Voltage regulation of a large transformer is mainly influenced by
A) No load current and load power factor

B) Winding resistances and load power factor

C) Leakage fluxes and load power factor

D) Winding resistances and core loss