Question

An electric motor converts
A. Electrical energy into light energy’
B. Electrical energy into mechanical energy
C. Light energy into electrical energy
D. Mechanical energy into electrical energy.

Answer 1

Hint: As we all know that we need to transform energy on a daily basis to fulfill conventional needs as energy available in one form needs to be transformed into other forms. For example, solar energy available in the form of heat can be converted into electricity through solar modules.

Complete step by step answer:
Electrical energy is the form of energy available in the form of flowing current and electric potential that is delivered to us with a proper circuit system. Now we know that we need an electric motor to run the shaft of a fan or a driving shaft. Maybe that is what we need is the rotation of the shaft. So a rotating shaft has kinetic energy which is a Mechanical form of energy.
So therefore we connect the electric motor to a circuit to run its shaft and we get the desired output as the rotation of the shaft having the mechanical kinetic energy. So electrical energy converts into mechanical energy.

$\therefore$ The correct option is (B).

Note:
We must keep in mind that all the energy available at one end is not converted 100 percent to the other form at the next end. Since while energy conversion, a lot of losses take place during transformation and hence to take that into account we need to introduce a factor called conversion efficiency. We can show it by an expression as ${\eta _{conv}} = \dfrac{{{E_2}}}{{{E_1}}}$
Here, ${\eta _{conv}}$ is the conversion efficiency which shows how much energy is converted from one form to another. ${E_1}$ is the primary energy available which needs to be converted and ${E_2}$ is the energy transformed from ${E_1}$. So from here we can see that ${E_2} < {E_1}$. So we can conclude that ${\eta _{conv}} < \,\,\,1$.