Physics Mcqs

When A.C current passes through a capacitor then the current relationship will be_______________?

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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

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 ?

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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)

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 ?

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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