1.

A resistance of `20ohms` is connected to a source of an alternating potential `V=220sin(100pit)`. The time taken by the current to change from its peak value to r.m.s. value isA. `0.2 sec`B. `0.25 sec`C. `25xx10^(-3) sec`D. `2.5xx10^(-3) sec`

Answer» Correct Answer - D
Peak value to r.m.s value means, current becomes `1/(sqrt(2))` times.
So form `i=i_(0)sin100pit implies 1/(sqrt(2))xxi_(0)=i_(0)sin100pit`
`implies sin(pi/4)=sin100pit implies t=1/400sec=2.5xx10^(-3)sec`


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