A 10 Ω resistance is connected across 220 V - 50 Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:

Step-by-step solution

⇒ i = i 0 sin ω t When i = i 0 i 0 = i 0 sin ω t 1 ⇒ ω t 1 = π 2   … ( 1 ) When i = i 0 2 i 0 2 = i 0 sin ω t 2 ⇒ ω t 2 = π 4   … ( 2 ) Time taken by current from maximum value to rms value, ⇒ t 1 - t 2 = π 2 ω - π 4 ω = π 4 ω = π 4 × 2 π f = 1 8 × 50 = 1 400 sec = 2 . 5   ms