PRO Electrical Engineering 1st Quiz 1-56

A conductor of length 1 meter moves at right angle to a magnetic field of flux density 1 WB/m² with a velocity of 25 m/s. What is the induced emf in the conductor?

• 25 V

• 50 V

• 75 V

• 100 V

It is difficult to magnetize steel because of its

• high density

• high retentivity

• low permeability

• high permeability

Present day capacitors which have high capacitance in small size use a dielectric of

• paper

• rubber

• ceramic

• mylar

The current-carrying capacity of a copper wire having twice the diameter of another copper wire is ______ as great.

• twice

• four times

• three times

• half

The output current corresponding to maximum efficiency for a transformer having core loss of 100 watts and equivalent resistance referred to secondary of 0.25 Ω is ______ amperes.

• 5

• 20

• 25

• 400

What kind of device is a diode?

• Bilateral

• Linear

• Unipolar

• Nonlinear

What is the value of inductance of a coil that induces 100 volts when the current changes at the rate of 2 mA in 2 microseconds?

• 1.02 H

• 0.4 H

• 0.01 H

• 0.1 H

In a generator, if the voltage regulation is 5.5% and the full-load voltage is 220 volts, what is the no-load voltage equal to?

• 232.8 V

• 240.3 V

• 230 V

• 226.4 V

If the line frequency is 60 Hz, the output frequency of a bridge rectifier is

• 30 Hz

• 60 Hz

• 120 Hz

• 240 Hz

At what frequency will a 100 µF capacitor offer a reactance of 100 Ω?

• 60 Hz

• 15.9 Hz

• 100 Hz

• 141.4 Hz