Question

Which of the following is based on the mechanical effect of electric current?
A. AC Dynamo
B. DC Dynamo
C. AC or DC motor
D. Electric Geyser

Answer 1

Hint:We are asked to state which of the given options works on the basis of mechanical effect of electric current. In order to answer this, we can start by taking the principle of each of the following options. This will lead us to the required solution.

Complete answer:
Let us start to state the working principle of each of the options one by one;
(A) AC dynamo: They work on the basic principle of Faraday's law of electromagnetic induction. This law states that an electromotive force (emf) is generated in a loop that carries current and is placed in a varying magnetic field.
(B) DC dynamo: This also works on the basis of Faraday’s law of electromagnetic induction.
(C) AC or DC motor: The basic principle of this is that, when a current carrying conductor is placed in a magnetic field, it experiences a mechanical force. We can find the direction of current, force and magnetic field using the Fleming's left hand rule. We can see that the third option is based on the mechanical effect of electric current as it experiences a mechanical force due to the presence of electric current and magnetic field.

Hence, option (C) is the right answer.

Note:The electric Geyser works on the principle of conservation of energy, which states that energy can neither be created nor be destroyed but it can only be transformed from one form to another. Here, electrical energy is converted into heat energy.