The AC mains domestic supply current in India changes direction in every 

CONCEPT:

AC Mains Supply Frequency

• Alternating Current (AC) in domestic power supply means the current changes direction periodically.
• The frequency of the AC mains supply in India is 50 Hz.
• One complete cycle of AC means it goes from positive to negative and back to positive.
• The time period (T) of one complete cycle is the reciprocal of the frequency (f).

EXPLANATION:

• Given the frequency (f) of AC mains supply in India is 50 Hz:
  • Time period (T) = 1 / f
  • = 1 / 50 seconds
  • = 0.02 seconds
• Since the current changes direction twice in each cycle (once every half cycle):
  • The direction changes every T/2 seconds
  • = 0.02 / 2 seconds
  • = 0.01 seconds
  • = 1/100 seconds

Therefore, the AC mains domestic supply current in India changes direction in every 1/100 seconds.