According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to
$\rho $
${\rho ^2}$
$\frac{1}{{\sqrt \rho }}$
$\frac{1}{\rho }$
A $60\, watt$ bulb operates on $220\,V$ supply. The current flowing through the bulb is
A $220 \; V , 50 \; Hz$ AC source is connected to a $25 \; V$, $5 \; W$ lamp and an additional resistance $R$ in series (as shown in figure) to run the lamp at its peak brightness, then the value of $R$ (in ohm) will be
The heat generated through $2 \,ohm$ and $8\, ohm$ resistances separately, when a condenser of $200\,\mu F$ capacity charged to $200\, V$ is discharged one by one, will be
Consider four circuits shown in the figure below. In which circuit power dissipated is greatest (Neglect the internal resistance of the power supply)
In the figure shown the power generated in $y$ is maximum when $y = 5\,\Omega $. Then $R$ is