Question

The electric current in a metallic wire flows due to:

• A. free electrons
• B. protons
• C. neutrons
• D. ions

Answer 1

Answer: (A)

free electrons

When metal is connected to a battery, the free electrons get accelerated due to the electric field (set up by the battery) and they gain velocity and energy. However, the passage is not smooth and the electrons collide with the lattice ion in which the ultimate gainer (of energy) is the ion. As we know the temperature of a body is related with the energy of vibrations of these ions, these collisions result in increase in temperature of the metal. Mainly due to the free electron.