Question

An electric iron is based upon the principle of:
A) Heating effect of current
B) Magnetic effect of current
C) Chemical effect of current
D) None of these

Answer 1

Hint: The main work of an electric iron is to heat up. So the main principle behind an electric iron is heating of material through current. The material used in it is a good conductor of heat which conducts heat evenly on its surface.

Complete step by step answer:
An electric iron is based upon the principle of heating effect of current. This principle states that when an electric current is passed through a conductor, it generates heat because of the resistance present in it. The resistance converts electrical energy into heat energy. The formula for the heat produced due to resistance and current is given by $H = {I^2}RT$. This principle has many applications like heater, electric iron etc. in these types of devices they generally have a coil whose resistance is much higher which in turn converts electricity into heat energy. Not all metals can convert into heat energy. Only some metals have this property.

The other given options do not have any role in these types of appliances where heating is required. The heat produced also depends on the voltage applied across the appliances. But more the current passing through more heat will generate. A good conductor of electricity does not show this property. The materials having high resistance can only show a heating effect.

Note: In an electric iron the material used has the property of heating. They do not show magnetic or chemical effects. Iron heating effect is required to meet its purpose. So we use those materials which convert electricity into heat.