Chapter 21 - AC Circuits - Learning Path Questions and Exercises - Exercises - Page 748: 13

a) $R=7.5Ohm$ b) $f=20Hz$ , $T=0.05sec$ c) $240W$

$I=8A sin (40\times pi \times t)$ $V=60V sin (40\times pi\times t)$ a) R=peak Voltage / peak current = $60/8=7.5Ohm$ b) $\omega= 2\times pi \times f=40\times pi$ Thus, $f=20Hz$ i.e. $T=1/f=0.05sec$ c) Average power = RMS current $\times$ peak voltage = (peak current/$\sqrt 2$)(peak voltage/$\sqrt 2$)=$\frac{60\times8}{2}=240Watt$