The voltage - current $(V-I)$ graph of a metallic conductor at two different temperature $T_{1}$ and $T_{2}$ is shown below. At which temperature is the resistance higher?

When temperature of the conductor is increased, then the collision frequency between current carries ( electrons ) and atoms increases. This results in

$10$ wires (same length, same area, same material) are connected in parallel and each has $1\Omega$ resistance, then the equivalent resistance will be

Six identical cells, each of emf of $6V$, are connected in parallel. The net emf across the battery is

The resistor of resistance R is connected to 25 V supply and heat produced in it 25 J sec. The value of R is