A Step$-$Down Transformer. A transformer connected to a

$120$ V $($rms$)$ ac line is to supply $12\mathrm{.}0$ V $($rms$)$ to a portable electronic de$-$

vice. The load resistance in the secondary is $5\mathrm{.}00.($a$)$ What should the

ratio of primary to secondary turns of the transformer be$?($b$)$ What rms

current must the secondary supply? $($c$)$ What average power is delivered

to the load? $($d$)$ What resistance connected directly across the $120$ V line

would draw the same power as the transformer? Show that this is equal

to $5\mathrm{.}00$ times the square of the ratio of primary to secondary turns