Question

AT.If charges move without collisions through the conductor, their kinetic energy would also change, so that the total energy is a) changed b) unchanged doubled d) halved​

Answer 1

When the charges move freely across the conductor (without collision)⇒

The Kinetic energy $\\ (K.E.)$ will increase:

$\\ Change \ in\ K.E\ (\Delta K.E.) >V \Delta Q\\ \\ Change \ in\ K.E\ (\Delta K.E.) > V I\Delta t\\\\where\ V= Voltage , I =current, \Delta t=time\ for \ which \ current \ flow$

$\\ V \Delta Q = VI \Delta t$

On the other hand, the Potential energy$\\ (P. E)$ of the charge will decrease by the same amount.

$\\ Change \ in\ P.E\ (\Delta P.E.) <V \Delta Q\\ \\ Change \ in\ P.E\ (\Delta P.E.) < V I\Delta t\\\\where\ V= Voltage , I =current, \Delta t=time\ for \ which \ current \ flow$

Hence, $\\ \Delta P.E. = - \Delta K.E.$

So, the Total energy remains unchanged.

The correct option is b) unchanged.