A fuse in a motor circuit provides protection against

overload
short-circuit and overload
open circuit, short-circuit and overload
none of the above

The correct answer is: B. short-circuit and overload.

A fuse is a safety device that is used to protect electrical circuits from damage caused by overloads and short circuits. An overload occurs when the current flowing through a circuit exceeds the rated current of the circuit. A short circuit occurs when there is a direct connection between the two terminals of a circuit, bypassing the resistance of the circuit.

When a fuse blows, it interrupts the flow of current in the circuit, preventing damage to the circuit and the equipment connected to it. Fuses are typically rated for a specific current, and should be replaced with a fuse of the same rating.

Option A is incorrect because a fuse does not provide protection against open circuits. An open circuit occurs when there is a break in the circuit, preventing current from flowing.

Option C is incorrect because a fuse does not provide protection against open circuits. An open circuit occurs when there is a break in the circuit, preventing current from flowing.

Option D is incorrect because a fuse does provide protection against short-circuits and overloads.