Electric Current and its Effects - Worksheets

 CBSE Worksheet-01

Class – VII Science (Electric Current and its Effects)

  1. Electric current is the flow of
    1. Proton
    2. Electron
    3. Neutron
    4. Positron
  2. Which of the following materials is a conductor?
    1. Silver
    2. Plastic
    3. Cloth
    4. Rubber
  3. A device which prevents or allow the current to flow through it
    1. Motor
    2. Conductor
    3. Switch
    4. Terminal
  4. When two or more cells are joined together it forms a
    1. Dynamo
    2. Transistor
    3. Battery
    4. Insulator
  5. Match the following:
    Column AColumn B
    a. Switchi. Heating effect
    b. Electric cellii. Insulator
    c. Rubberiii. Produce electricity
    d. Copperiv. Close and open the circuit.
    e. Electric heaterv. Conductor
  6. Fill in the blanks.
    1. A group of two or more cell is called a _________.
    2. A device that breaks the circuit is called a _________.
    3. In electric circuit the electrons flow from _________ terminal to the _________ terminal.
    4. Metals are _________ conductor.
    5. A device which converts electric energy into light energy is _________.
  7. Why do we use nichrome in an electric heater?
  8. What is a fuse? Write its function?
  9. Write difference between a cell and a battery?
  10. Give one word for the following:
    1. Path of electric circuit
    2. A device that create potential difference.
    3. Coming together of live and neutral wire in a circuit.
    4. A safety device that protects appliances from overloading and short circuit.
    5. Magnet produced by electricity.

CBSE Worksheet-01
Class – VII Science (Electric Current and its Effects)
Answer key

  1. b
  2. a
  3. c
  4. c
  5. (a) – (iv), (b) – (iii), (c) – (ii), (d) – (v), (e) – (i).
    1. Battery
    2. Switch
    3. Negative, Positive
    4. Good
    5. Bulb.
  7. Nichrome wire is used as a heating element in electric heater because it is very stable, even at high temperatures. Unlike other metals, it will not melt even when generating large amounts of heat.
  8. Fuse is a safety device made up of alloy having low melting point. It is connected in series in the circuit. It protects the circuit and electrical appliances in case of excess of current in the circuit.
  9. cell is a device that creates potential difference in the circuit to flow the current in the circuit. Combination of two or more cells in series is called a battery.
    1. Electric circuit
    2. Battery or cell
    3. Short circuit
    4. Fuse
    5. Electromagnet.