A. fluctuates off and on
B. varies in magnitude alone
C. changes its direction again and again
D. changes its magnitude harmonically and reverses its direction of flow after regularly recurring intervals
Related Mcqs:
- An alternating current is represented by the equation I = I∫sinπt which of the following equation represents an alternating current of frequency and amplitude twice that of the above current ?
A. I = 2I∫Sin(πt/2)
B. I = 2I∫Sin(2πt)
C. I = 2ISinπt
D. I = I∫sin(2πt) - The value of the steady current which when flowing through the same resistor produces heat at the same rate as the mean rate of heat produced by the alternating current is__________________?
A. Average current
B. Sinusoidal current
C. r.m.s current
D. Net current - An alternating current of the r.m.s value of 4.0 A and frequency 50Hz flows in a circuit containing a 10Ω resistor. The peak current is then ?
A. 20A
B. 20.66A
C. 6.66A
D. 5.66A - To find the r.m.s value of an alternating current mathematically we need to have ________________?
A. Mean value of I2
B. Square root of mean value of I2
C. Square root of I2
D. Square of 1/2 - The alternating voltage is an example of_______________?
A. A digital waveform
B. An analogue waveform
C. Discrete waveform
D. None at all - When A.C current passes through a capacitor then the current relationship will be_______________?
A. The current lead voltage by phase angle is 90 degrees
B. The voltage leads current by phase angle is 90 degrees
C. The current lead voltage by phase angle is 45 degrees
D. The voltage leads current by phase angle is 45 degrees - pure resistor circuit the voltage and current are_______________?
A. Lagging each other
B. They are at 90? phase difference
C. They have zero phase difference
D. No phase difference - What is the self-inductance of a coil in which an induced emf of 2V is set up when the current changes at the rate of 4 As-1 ?
A. 0.5 mH
B. 0.5H
C. 2.0H
D. 8.0H - An inductive coil has a resistance of 100Ω. When an AC signal of frequency 1000Hz is fed to the coil the applied voltage leads the current by 45Ω. What is the inductance of the coil ?
A. 10mH
B. 12mH
C. 16mH
D. 20mH - Two identical coaxial circular loops carry equal currents in the same direction. If the loops approach each other the current in______________?
A. Each increase
B. Each decrease
C. Each remains the same
D. One increases whereas that in the other decreases
