The frequency of domestic power supply in Pakistan is_________?

A. 200 hz
B. 100 hz
C. 60 hz
D. 50 hz

In a three-phase supply floating neutral is undesirable because it way give rise to___________?

A. High voltage across the load
B. Low voltage across the load
C. Unequal line voltages across the load
D. Minimun voltage across the load

The r.m.s. value of half wave rectified sine wave is 200 V. The r.m.s. value of full wave rectified AC. will be___________?

A. 282.8 v
B. 141.4 v
C. 111 v
D. 100 v

Which of the following waves has the highest value of peak factor ___________?

A. Square wave
B. Sine wave
C. Half wave rectified sine wave
D. Triangular wave

The inductance of a coil can be increased by_________?

A. Increasing core length
B. Decreasing the number of turns
C. Decreasing the diameter of the former
D. Choosing core material having high relative permeability

The phosphors for which of the following pair are 180° out of phase for VL, VC and VR______?

A. Vc and vr
B. Vl and vr
C. Vc and vl
D. None of the above

The r.m.s. value of pure cosine function is_________?

A. 0.5 of peak value
B. 0.707 of peak value
C. Same as peak value
D. Zero

The series and parallel resonance on L-C circuit’ differs in that_________?

A. Series resistance needs a low-resistance source for sharp rise in current
B. Series resonance needs a high-resistance source for sharp increase in current
C. Parallel resonance needs a low-resistance source for a sharp in¬crease in impedance
D. Parallel resonance needs a low-resistance source for a sharp rise in line current

The frequency of an alternating current is____________?

A. The speed with which the alternator runs
B. The number of cycles generated in one minute
C. The number of waves passing through a point in one second
D. The number of electrons passing through a point in one second

Ohm is unit of all of the following except___________?

A. Inductive reactance
B. Capacitive reactance
C. Resistance
D. Capacitance