1. A bulb has
(a) two terminals and one filament
(b) two terminals and two filaments
(c) multiple terminals and single filament
(d) single terminal and single filament
Answer: (a) two terminals and one filament
2. Filament of a bulb is made up of
(a) aluminium
(b) chromium
(c) platinum
(d) tungsten
Answer: (d) tungsten
3. A battery is
(a) a single cell
(b) a combination of cells in which cells are joined (+) to (-)
(c) a combination of cells in which cells are joined (+) to (+)
(d) None of these
Answer: (b) a combination of cells in which cells are joined (+) to (-)
4. A substance which allows electricity to pass through it is called
(a) a conductor
(b) an insulator
(c) semiconductor
(d) superconductor
Answer: (a) a conductor
5. Which is an example of an insulator
(a) bakelite
(b) aluminium
(c) tap water
(d) All of these
Answer: (a) bakelite
Column A Column B
(a) Cell (i) Allows electricity to pass through it
(b) Battery (ii) in Either breaks or completes a circuit
(c) Conductor (iii) Converts electricity into light
(d) Insulator (iv) Glows when electricity passes in it
(e) Switch (v) A device which produces electricity
(f) Bulb (vi) Does not allow electricity to pass
(g) Filament (vii) A combination of cells
ANSWERS
Column A Column B
(a) Cell (v) A device which produces electricity
(b) Battery (vii) A combination of cells
(c) Conductor (i) Allows electricity to pass through it
(d) Insulator (vi) Does not allow electricity to pass
(e) Switch (ii) in Either breaks or completes a circuit
(f) Bulb (iii) Converts electricity into light
(g) Filament (iv) Glows when electricity passes in it
Question 1.
What is electric circuit?
Answer:
Path from one terminal of the electric cell to the other terminal of the electric cell through wires passing to and from the electric bulb is called electric circuit.
Question 2.
What is a filament?
Answer:
A filament is a thin wire fixed in the middle of a bulb connected to the two supporting wires.
Question 3.
What is a conductor? Give examples.
Answer:
A conductor is a material that allows an electric current to pass through it. For example, copper, aluminium, zinc, iron, etc.
Question 4.
What is an insulator? Give few examples.
Answer:
Insulator is the material that does not allow an electric current to pass through it. For example, wood, mica, asbestos, rubber, etc.
Question 5.
Why is the handle of electrician’s screw driver made of plastic?
Answer:
A screw driver is made of steel. It is a good conductor of electricity. So electricity can easily flow through it. Plastic is a bad conductor and does not allow electricity to pass through it. So, the electrician has a plastic handle to protect him from any shock.
