question_answer

The time taken by an alternating current of 50 Hz in reaching from zero to its maximum value will be :

A)  0.5 s                                     

B)  0.005 s

C)  0.05 s                                   

D)  5 s

Correct Answer: B

Solution :

                 An alternating current is one whose magnitude changes continuously with time between zero and a maximum value and whose direction reverses periodically. The relation between frequency\[(f)\]and time (T) is \[T=\frac{1}{f}=\frac{1}{50}=0.02\,s\] As is clear from the figure time taken to reach the maximum value is \[\frac{T}{4}=\frac{0.02}{4}=0.005\,s\]