ARMY PUBLIC SCHOOL, RK PURAM
Class VII Science Worksheet
Ch-3 Electricity: Circuits and their components
Multiple Choice Questions (MCQs)
1. Which of these is not an insulator?
a) Wood b) Rubber
c) Copper d) Plastic
2. What is the purpose of a switch?
a) Store electricity b) Break or complete the circuit
c) Generate electricity d) Heat the wires
3. In which condition does a bulb not glow?
a) When the switch is “OFF” b) When the circuit is open
c) When the circuit is closed d) Both a and b
4. The wire inside a bulb that glows is called
a) Conductor b) Filament
c) Fuse d) Switch
5. A combination of cells is called
a) Fuse b) Wire
c) Switch d) Battery
6. What does an LED do in a circuit?
a) Generate electricity b) Produce light
c) Reduce voltage d) Measure current
7. What are the small, flat, round batteries often used in watches and hearing aids called?
(a) Cylindrical cells (b) Button cells
(c) Rechargeable batteries (d) Solar cells
8. How does an incandescent lamp differ from an LED in terms of polarity requirement?
(a) Both require specific polarity.
(b) Neither requires specific polarity.
(c) Incandescent works either way; LED requires specific polarity.
(d) LED works either way; Incandescent requires specific polarity
9. In _________________ filament gets hot and produces light.
a) incandescent lamp b) fluorescent lamp
c) LED d) None of these
10. In an electric circuit diagram, a cell is represented by:
a) A zigzag line b) A circle
c) Two parallel lines of different lengths d) A rectangle
Questions below consist of two statements – Assertion (A) and Reason (R). Answer these
questions by selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true
(e) Both A and R are false
11. Assertion (A): Electricity from batteries is a type of direct current (DC).
Reason (R): DC of batteries are used to power small devices.
12. Assertion (A): Copper is used in making electric wires.
Reason (R): Gold is a bad conductor of electricity.
13. Assertion (A): Rubber is used to cover electric wires.
Reason (R): Rubber is an insulator and prevents electric shock.
Short Answer Questions
14. Draw the symbols for a) LED b) electric lamp c) battery
15. Give examples for good conductors and insulators.
16. What is the function of a switch in a circuit, represent it using the appropriate symbol?
17. Why does the filament of a bulb glow?
18. Suppose the ‘+’ and ‘–’ symbols cannot be read on a battery. Suggest a method to
identify the two terminals of this battery.
Long Answer Questions
19. Explain the construction and working of an electric bulb.
20. Differentiate between conductors and insulators
21. Draw separately two labelled diagrams of an electric circuit with a bulb and a switch in
‘ON’ and ‘OFF’ position respectively.
Case Based Question
Arjun is building a simple circuit tester like the one in Figure (a). He uses a cell, a small LED
and wires. He tests it by touching the free wire ends together, but the LED doesn’t light up. He
checks the cell is new and the wires are properly stripped. He knows LEDs work differently
from incandescent lamps.
1. What is the most likely reason the LED is not lighting up, assuming the cell and wires
are fine?
2. How should Arjun connect the wires from the cell to the LED’s terminals (longer and
shorter wires) to make it glow?
3. If Arjun replaces the LED with a small incandescent lamp from a torch, would he
need to worry about connecting it in a specific direction? Why or why not?
