Question

Find an odd man out.
Water heater, Electric kettle, Electric iron, Electric fuse
A) Water heater
B) Electric kettle
C) Electric fuse
D) Electric iron

Answer 1

**Hint :**We know that all the electric devices listed above are in one way or another related to electricity. Three of the devices are electrical appliances while one of them is a safety device.
It will be easier for us to answer once the working of each device is known.

Complete answer:
In order to answer this question let's first understand what these devices are used for and what their working principle is:

Water heater: The Water heater uses the operational principle of a heat pump, by absorbing calories in air and using this energy to ensure water heating.

Electric kettle: An electric kettle is an electrical appliance which has its own self heating unit, for heating water, and automatically switches off when the water reaches boiling point or some temperature value set by the user.

Electric fuse: The working principle of electric fuse is based on the principle of heating effect of electric current. It is made up of thin metallic wire which has a relatively lower melting point. When an excessive current flows in the circuit, it generates heat in the circuit which leads to melt the fuse, and it also opens the circuit as a result flow of current is disturbed. Henceforth it saves other electrical appliances.

Electric iron: The working principle of electric iron is that heat is produced in the nichrome wire used in the iron due to the current flowing through it. This heat is then transferred to another metallic plate which is placed at the bottom of iron.

Since, all of the above except Electric fuse is an electrical appliance while electric fuse is a safety device; therefore, the correct option is C, that is, Electric fuse.

**Note :**In these types of questions try to find a relation which is common for three options and which is absent for others. This question requires understanding of the working principles of electric devices as all the options are electric devices so it may get confusing.