Question

The root-mean-square value of an alternating current of $50Hz$ frequency is $10$ ampere. The time taken by the alternating current in reaching from zero to maximum value and the peak value of current will be:

• A. $2\times {10}^{-2}$ sec and $14.14$ amp
• B. $1\times {10}^{-2}$ sec and $7.07$ amp
• C. $5\times {10}^{-3}$ sec and $7.07$ amp
• D. $5\times {10}^{-3}$ sec and $14.14$ amp

Answer 1

The correct option is D $5\times {10}^{-3}$ sec and $14.14$ amp

$I_p=\sqrt{2}\times V_{rms}10\times \sqrt{2}=14.14Am$

Time taken

$t=\frac{T}{4}=\frac{2\pi }{2\pi f\times 4}=\frac{1}{4f}=5\times {10}^{-3}sec$