KCET2019PhysicsAlternating Current
The frequency of an alternating current is ( 50 ~Hz ). What is the minimum time taken by current to reach its peak value from rms value?
Options
- A( 0.02 ~s )
- B( 5 10⁻³ s )
- C( 10 10⁻³ )
- D( 2.5 10⁻³ ~s )
Correct answer
D. ( 2.5 10⁻³ ~s )
Step-by-step solution
(D) We know that ( v_ r m s =v₀ t ) ( v₀ 2 =v₀ t ) ( t= ( 1 2 ) ) i.e., ( t= 4 2 T t= 4 ) ( t= T 8 ) Time for current to reach from rms value to peak value is i.e., ( I_ r m s I₀ ) ( T 4 - T 8 = T 8 ( I₀ 2 I₀ ) ) ( f=50 t= I 8 ) ( = 1 50 8 = 1 400 =0.25 10⁻² ) ( =2.5 10⁻³ ~s ) ( [ D ] ) is correct.