Class VI Physics: Chapter: Electrical circuit

Quest Time CBSE NCERT VI Chapter: Electric currents, Circuits, Cell.

1. From where do we get electricity?

Ans: A power station provides electricity. If the supply of electricity may fail we use other sources of energy like torch at home.

2. Why does the bulb glow switch on a torch?

Ans: It glows because the electric energy stored in the electric cells is converted into light energy by the bulb.

Hence Electric cell is a source of light energy.

3. Name the scientist who developed first Cell?

Ans: The first electric cell was developed by an Italian scientist Luigi Galvani and then improved by Alessandro Volta.

4. Name a cell that is recharged by Light of The Sun?

Ans: alkali cells and solar cells. Solar cells convert light energy into electric energy.

5. What is an electric cell?

Ans: An electric cell is a device which converts chemical energy into electric energy.

The cell has two different metal plates – one is the positive terminal and the other is the negative terminal. These plates are kept inside a chemical called electrolyte. One of the chemical is white in color NH₄Cl (Ammonium chloride) and other is a black powder MnO₂ (manganese dioxide).

6. What is an electric current?

Ans: Electric current is the flow of electrons or charge. The cell is a source of electric current.

7. What is an electric circuit?

Ans: An electric circuit is the closed path along which electric current flows from the positive terminal to the negative terminal of the battery.

A circuit generally has:

a) A source of electric current - a cell or battery(A group of cell called battery)

b) Connecting wires for carrying current.

c) A device which uses the electricity - a bulb ( Bulb is a device that convert electrical energy into light)

d) A key or a switch – A component of circuits that stop or allow the flow of current. When the current flows the circuit is said to be closed circuit.  When the current does not flow, the circuit is said to be open circuit.

8. How does a bulb glow and produce light?

Ans: Inside the bulb there is a thin coil of wire made of tungsten, called filament. It gets heated and glows when the current flows. Hence, electric energy is converted into light energy by a bulb.

9. If the filament inside the bulb is broken will the bulb glow? Why?

Ans: The circuit is not complete; current does not flow through the circuit and the bulb does not glow.

10. Why do we feel warm when we touch the lighted bulb?

Ans: The bulb also emits heat energy along with light.