more about resistance

What is the total resistance of components connected in series?

The sum of the individual resistances

What is the total resistance of components connected in parallel?

The sum of the reciprocals of the resistances

What is the heating effect of an electric current due to?

Resistance

Explain the heating effect

The charge carriers repeatedly collide with positive ions of the conducting material. There is a net transfer of energy from the charge carriers to the positive ions as a result of these collisions. After a charge carriers lose energy loses KE in such a collision, the force due to the pd across the material accelerates it until it collides with another positive ions

Using F = ma, explain the heating effect of a current in terms of collisions.

The force due to the pd accelerates charge carriers between collisions. In each collision with a positive ion, the charge carrier transfers KE to the ion. This increases the KE of the lattice, raising the temperature of the material

Explain using F = ma why increasing pd increases current

A larger pd = a larger force on charge carriers. F = ma, so therefore a greater acceleration between collisions, so charge carriers arrive at positive ions with more KE, so more charge passes per second, current increases.