




$(i) R = r$ $(ii)$ Power in $R$ is $\frac{{{E^2}}}{{4R}}$
$(iii)$ Input power $\frac{{{E^2}}}{{2R}}$ $(iv)$Efficiency is $50\%$
$Y :$ The resistivity of a semiconductor decreases with increases of temperature.
$Z :$ In a conducting solid, the rate of collision between free electrons and ions increases with increase of temperature.
Select the correct statement from the following :