Question

An air conditioner of 2kW is used in an electric circuit having a fuse of 10A rating. If the potential difference of supply 220V is applied, will the fuse be able to withstand when the air conditioner is switched on? Justify.

Answer 1

Hint: Like switch, bulb, etc. which are present in electrical circuit boards, we have fuse wire also and is a very important part of the circuit which plays an important role in protecting the appliances from getting destroyed due to heavy voltage fluctuation. It consists of a thin wire which has a very low melting point.

Formula used: $P=VI$

Complete step by step answer:
Fuse wire is present in almost every modern electrical equipment or device. It works on the principle of heating effect of electric current. It works such that when current, more than a particular value is passed through the wire, due to the heating effect of electric current it gets melted. The reason behind the melting of wire is its low melting point. Once this wire gets melted, the current stops flowing into the circuit and hence the equipment gets saved from high voltage fluctuation.
Now, the rating of the fuse is 10A which means that the current shall remain less than 10A for safe usage of air conditioner.
Now the power rating of the air conditioner is 2kW and voltage is 220V.
Thus using P=VI, we get
$I = \dfrac PV = \dfrac{2\times 10^3}{220} = 9.09 A$

Hence we see that the value of current is less than 10A. Hence the fuse can withstand the load.

Note:
Fuse wire is a delicate material wire. It is made up of zinc, copper, silver, aluminum or the alloys to provide suitable and predictable characteristics. The wire is connected in series with the appliance such that all the current could be passed through the wire first and then reach the appliance. This ensures the safety of the appliance.