In the capacitive circuit the current___________________?
(A) Lags behind voltage by π/2
(B) Is in phase with voltage
(C) Opposite in phase of voltage by π
(D) Leads forward the voltage by π/2
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
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)
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
A capacitor of capacitance 30µF is charged by a constant current of 10mA. If initially, the capacitor was uncharged what is the time taken for the potential difference across the capacitor to reach 300V ?
(A) 0.9sec
(B) 15 sec
(C) 1.5x105sec
(D) 0.9x102sec
Electromagnetic waves emitted from antenna are________________?
(A) Stationary
(B) Longitudinal
(C) Transverse
(D) All the above
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
An A.C series circuit containing 4Ω resistance and 3Ω inductive reactance. The impedance of the circuit is______________?
(A) 1Ω
(B) 5Ω
(C) 7Ω
(D) 7Ω