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

$A$ bulb has a specification of $1\, kW$ and $250\, V$. The resistance of the bulb is .................. $\Omega$.

$A$ battery with $EMF$ $E$ and internal resistance $r$ is connected across a resistance $R$. The power consumption in $R$ will be maximum when:

Which of the following curves represents the relationship between the heat produced in a resistor and the current flowing through it?

Two electric lamps of $40\, W$ each are connected in parallel. The power consumed by the combination will be ........... $W$.

$A$ circular wire has a current density $J = (2 \times 10^{10} \text{ A/m}^2) r^2$, where $r$ is the radial distance from the center and the wire radius is $2 \text{ mm}$. The potential difference applied across the wire is $50 \text{ V}$. How much energy (in Joules) is converted to thermal energy in $100 \text{ s}$ (in $\pi$)?