Sunita had to replace the electrical plug of her clothes iron. She bought a three-pin plug as shown below.

When she removed the old plug, she saw that there were three wires coloured red, black and green.
(a) Direct contact between which of the three coloured wires will result in a short circuit?
(b) State what happens to the current in the circuit in the case of a short circuit. Give a reason for your answer.