Question

an alternating current has frequency of 50 Hz how many times does it changes its direction in one second

Answer 1

If frequency is 50Hz, we know that time period for one full "oscillation" or AC wave, is 1/50 sec, But in one cycle, direction changes twice. So, every half time period, polarity is reversed, so every 1/100th sec. Which implies that, in 1 sec, direction changes 100 times.

Answer 2

Number of times ac changes its direction in one second is 100.

• Alternating current(ac) is the electric current which reverses its direction periodically.
• One ac oscillation consists of one positive half cycle and one negative half cycle.
• In the given question, frequency of ac is 50 Hz i.e, there are 50 positive half cycles and 50 negative half cycles.
• The direction changes after every half cycle.
• Therefore, the direction of an alternating current having frequency 50 Hz changes 100 times in one sec.