Answer:
1. direct current 2. induction 3. conduction
Step-by-step explanation:
When we walk barefoot on a carpet there is friction between the carpet surface and the lower surface of the feet which results in the exchange of charges between the two surfaces. During this course the carpet loses electron to the surface of the foot. Now, the charge on the carpet is static because it is an insulator but a human body being a good conductor of electricity has mobility of the charges.(3)
These mobile charges on the surface of a human body spread and look for a path of dissipation to a reservoir. When we bring our hand near a metal it induces an opposite charge near the surface of the metal,(2) this happens within a fraction of seconds. Now there is a positive charge on the nearest point on the metal and the negative charge on its farthest end is induced according to the conservation of charges.
As soon as the hand touches the metal (1)there is a transfer of charge from our body to the metal generating a very small shock. This happens only if we continue to stand on an insulated surface due to which the charge doesn't gets transferred to the ground.