Q: Which force out of four fundamental forces is involved during handshake?

A: The force involved during a handshake is the electromagnetic force, which is one of the four fundamental forces of nature. The electromagnetic force is responsible for the interaction between charged particles, such as the protons and electrons in atoms. When two people shake hands, the electromagnetic force between the electrons in their respective hands creates a repulsive force, which gives the sensation of a solid handshake.