A. a line which represents the magnitude and phase of an alternating quantity
B. a line representing the magnitude and direction of an alternating quantity
C. a coloured tag or band for distinction between different phases of a 3-phase supply
D. an instrument used for measuring phases of an unbalanced 3-phase load
Related Mcqs:
- Power factor of an inductive circuit is usually improved by connecting capacitor to it in____________?
A. parallel
B. series
C. either A. or (b)
D. none of the above - The form factor is the ratio of_______?
A. peak value to r.m.s. value
B. r.m.s. value to average value
C. average value to r.m.s. value
D. none of the above - If two sine waves of the same frequency have a phase difference of JT radians, then_______?
A. both will reach their minimum values at the same instant
B. both will reach their maximum values at the same instant
C. when one wave reaches its maxi¬mum value, the other will reach its minimum value
D. none of the above - Time constant of an inductive circuit___________?
A. increases with increase of inductance and decrease of resistance
B. increases with the increase of inductance and the increase of resistance
C. increases with decrease of inductance and decrease of resistance
D. increases with decrease of inductance and increase of resistance - In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters ______?
A. 220 V
B. 220V3V
C. 220/V3 V
D. none of the above - 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 - In a parallel R-C circuit, the current always________the applied voltage?
A. lags
B. leads
C. remains in phase with
D. none of the above - All definitions of power factor of a series R-L-C circuit are correct except__________?
A. ratio of net reactance and impedance
B. ratio of kW and kVA
C. ratio of J and Z
D. ratio of W and VA - The safest value of current the human body can carry for more than 3 second is_________?
A. 4 mA
B. 9 mA
C. 15 mA
D. 25 mA - In a series L-C circuit at the resonant frequency the__________?
A. current is maximum
B. current is minimum
C. impedance is maximum
D. voltage across C is minimum
