The heat developed in an electric wire of resistance $R$ by a current $I$ for a time $t$ is

Two electric bulbs of $40 \text{ W}$ each are connected in series. The power consumed by the combination will be . . . . . . . (in $\text{ W}$)

The maximum current that flows through a fuse wire before it blows out varies with its radius as

What is the maximum voltage that can be safely applied across a resistor of $196 \,\Omega - 1 \,W$ rating? .......... $volt$

$A$ potential $V_0$ is applied across a uniform wire of resistance $R$. The power dissipation is $P_1$. The wire is then cut into two equal halves and a potential of $V_0$ is applied across the length of each half. The total power dissipation across two wires is $P_2$. The ratio $P_2: P_1$ is $\sqrt{x}: 1$. The value of $x$ is $.............$.

Two bulbs are rated $(40 \; W, 200 \; V)$ and $(100 \; W, 200 \; V)$. What is the correct relation for their resistances?