A current i passes through a wire of length $l$, radius of cross-section $r$ and resistivity $\rho$. The rate of heat generation is
$\frac{{{i^2}l\rho }}{{\pi {r^2}}}$
${i^2}{\left( {\frac{{l\rho }}{{\pi {r^2}}}} \right)^2}$
${i^2}l\,\rho \,/\,r$
$i\,l\,\rho \,/\,r$
Wheat stone bridge is balanced. Find ratio of electric power dissipated in $(P + Q)$ to $(R + S)$
A $3\,^oC$ rise in temperature is observed in a conductor by passing a certain current. When the current is doubled, the rise in temperature will be ............. $^oC$
The value of the resistance $R$ in figure is adjusted such that power dissipated in the $2\,\Omega$ resistor is maximum. Under this condition
Which of the following statement is false
Time taken by a $836\; W$ heater to heat $1\; litre$ of water from $10^{\circ} C$ to $40^{\circ} C$ is