Explanation:
Given, \({I_{rms}} = 10\;A\)
and \(\,\,\,\,\,\,\,\,\,\,R = 12\,\Omega \)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{E_{rms}} = {I_{rms}} \times R\)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 10 \times 12 = 120\;V\)
Now, maximum potential difference
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = {E_{rms}} \times \sqrt 2 = 120 \times \sqrt 2 \)
\(\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 169.68\;V\)