In a pure resistive circuit__________?
(A) current lags behind the voltage by 90°
(B) current leads the voltage by 90°
(C) current can lead or lag the voltage by 90°
(D) current is in phase with the voltage
In a circuit containing R, L and C, power loss can take place in____________?
(A) C only
(B) L only
(C) R only
(D) all above
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
The equation of 50 Hz current sine wave having r.m.s. value of 60 A is____________?
(A) 60 sin 25 t
(B) 60 sin 50 t
(C) 84.84 sin 3141
(D) 42.42 sin 314 t
The power factor of a D.C. circuit is always__________?
(A) less than unity
(B) unity
(C) greater than unity
(D) zero
In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will__________?
(A) be reduced by half
(B) be doubled
(C) be four times as high
(D) be reduced to one fourth