What are the differences between electric motor and electric generator?

Chapter No. 4. Effect of Electric Current.

What are the differences between electric motor and electric generator?

Ans.

Electric Motor	Electric Generator
It converts electrical energy into mechanical energy.	It converts mechanical energy into electric energy.
A battery is used as source of electric energy in the circuit.	No source of electric energy is connected in the circuit.
A coil is set into rotation in presence of magnetic field, when current flows through the coil.	The coil set into rotation in presence of magnetic field by external arrangement generates potential difference and in turn current.
Split rings are used in electric motor.	Conducting rings are used in electric generator.

What are the difference between alternating current and direct current?

Chapter No. 4. Effect of Electric Current,

What are the difference between alternating current and direct current?

Ans.

Alternating current	Direct Current
Alternating current varies in magnitude continuously, i.e., oscillatory.	Magnitude of direct current from a source remains same, i.e., non oscillatory.
Direction reverses periodically, i.e. after equal intervals of time.	Direction remains same.
This type of current is used in electrical household appliances such as electric heater, refrigerator, electric iron, etc.	This type of current is not used much for household purposes but used in batteries, torches, etc.
Frequency of A.C. in India is 50 Hz, i.e., its cycle changes in 1/50 second.	Frequency of D.C. is zero.
Produced by A.C. generator.	Produced by D.C. generator.
Graphical Representation:	Graphical representation: