Question

State whether following statements are True or False:
A. An electric motor converts mechanical energy into electrical energy.
B. An electric generator works on the principle of electromagnetic induction.
C. The field at the center of a long circular coil carrying will be parallel straight lines.
D. A wire with a green insulation is usually the live wire of an electric supply.

Answer 1

Here, just follow the given terminologies and different concepts applicable to the given statements and verify whether the given statements are true or false. Also, be careful about the terms and difference between an electric motor and an electric generator.
Insulation is used to prevent the electrical shock and different colours of wire such as red, black and green are used.

Complete step by step answer:
a. An electric motor is an electrical machine which converts the electrical energy into mechanical energy.
So, the given statement - An electric motor converts mechanical energy into electrical energy is false.

b. An electric generator works on the principle of the electromagnetic induction which was discovered by Michael Faraday. It was found that the flow of current can be created by moving an electrical conductor in the magnetic field. The movement creates the voltage difference between the two ends of the conductor causing the electric charges to flow, hence generating electric current.
So, the given statement - An electric generator works on principle of electromagnetic induction is true.

c.

As shown in the above figure, the magnetic field lines at the centre of the long circular coil carrying current are parallel straight lines.
So, the given statement - The field at the center of a long circular coil carrying parallel straight lines is true.

d. The live wire has the red colour insulation cover and the earth wire has green colour insulation in the domestic circuits. Usually the green insulation is used for grounding an electrical circuit.
So, the given statement - A wire with a green insulation is usually the live wire of an electric supply is false.

Note: Verify the given word statements twice and keep in mind the terminologies to get the required answer. Remember an electric motor and electric generators are two different electrical machines. An electric motor converts electrical energy to mechanical energy whereas; an electrical generator is a machine which converts mechanical energy to electrical energy.