Question

Why internal resistance decreases with increase in temperature?

Answer 1

internal resistance decreases with increase in temperature because, the kinetic energy and mobility (movement) of the particles is increased.

# consider a conducting material. It is made up of atoms.

# electricity is conducted due to the movement of electrons from one end to the other.

# resistance is the ability of the material to stop the movement of electrons and thereby, restricting the flow of electricity.

# when temperature is increased, heat energy is transformed into kinetic energy which increase the movement of the electrons.

# thus the mobility is increased. As the mobility is increased, current flowing through the conductor increases.

# from ohm's law, for constant voltage applied, product of current and resistance remains constant.

V = I*R

So, if current increases, resistance decreases. Since current and resistance are inversely proportional to eachother under constant voltage.

Thus, internal resistance decreases with increase in temperature