ALTERNATING CURRENT | ADHYAYAN IAS

Introduction

AC is defined as alternating current due to bidirectional flow and representing by Sinusoidal current because of sine function . we just giving few important questions related to ac

.1 In a light bulb connected to an ac source the instantaneous current is zero two times in each cycle of the current. Why does the bulb not go off during these times of zero current?

2. An electric iron having a resistance 25Ω is connected to a 220V, 50 Hz house hold outlet. Determine the average current over the whole cycle, peak current, instantaneous current and the rms current in it.

3. Why is it necessary to calculate root mean square values of ac current and voltage.

4. Explain why current in a capacitor connected to an ac generator increaseswith capacitance.

5. A capacitor is connected to an ac generator having a fixed peak value (Vm) but variable frequency. Will you expect the current to increase as the frequency decreases?

6. Will average power delivered to a capacitor by an ac generator to be zero? Justify your answer.

7. Why do capacitive reactances become small in high frequency circuits, such as those in a TV set?