Short Questions: Electricity and Circuit | NCERT Summary: UPSC PDF Download

Q1: How does a light bulb produce light?
Ans: A thin wire like structure known as filament is present inside the bulb. When we switch on the bulb, electricity passes through filament causing it to heat up and glow to produce light. In this process the electric energy changes into light energy.

Q2: How does a bulb fuse?
Ans: Inside the bulb there is a thin wire like structure called filament. Filament is made of substances having a low melting point. Filament gets heated and emits light when we switch on the bulb. But when there is excess flow of current through the filament it melts down due to excessive heat. This causes fusing of the bulb.

Q3: Label the parts in the following diagram. Indicate the positive and negative terminals.
Ans:

Q4: What is an electric circuit?
Ans: The closed path in which electric current flows is called an electric circuit. Generally, an electric circuit consists of wire, battery, switch and an appliance which needs electricity to work. The current in the electric circuit flows from the positive terminal to the negative terminal. The switch is used to break the flow of the current when the appliance is not in use.

Q5: Explain the role of a switch in a circuit. What is it made up of?
Ans: An electric switch is a circuit component that can be used to control the flow of electricity through the circuit. It has the ability to both complete and break the circuit. A conducting substance is used to make the switch. The circuit is complete and power flows through it when the switch is in the "ON" position. The circuit is broken and power cannot flow through it while the switch is in the "OFF" position.