Electricity: Circuits and their Components
Multiple Choice Questions Based on NCERT Class 7 Science, Chapter 3 Electricity : Circuits and their Components :
MCQs :
1. Which of the following is used to represent an electric component in a circuit diagram?
(a) Symbols
(b) Pictures
(c) Sketches
(d) Graphs
2. A combination of two or more cells is called a:
(a) Fuse
(b) Battery
(c) Circuit
(d) Switch
3. In a circuit diagram, the longer line in the symbol for a cell represents:
(a) Negative terminal
(b) Positive terminal
(c) Neutral terminal
(d) Direction of flow
4. When the switch is in the 'OFF' position, the circuit is said to be:
(a) Closed
(b) Open
(c) Complete
(d) Overloaded
5. Which effect of electric current is used in an electric heater?
(a) Magnetic effect
(b) Chemical effect
(c) Heating effect
(d) Lighting effect
6. The wire used in a fuse has a:
(a) High melting point
(b) Low melting point
(c) Low resistance
(d) Very high thickness
7. Who discovered the magnetic effect of electric current?
(a) Isaac Newton
(b) Hans Christian Oersted
(c) Thomas Edison
(d) Michael Faraday
8. The heating element of an electric iron is made of:
(a) Copper
(b) Nichrome
(c) Iron
(d) Aluminum
9. A safety device used in electrical circuits to prevent fire and damage is:
(a) Electromagnet
(b) Battery
(c) Fuse
(d) Switch
10. The thin wire inside an electric bulb that glows when current passes through it is called:
(a) Element
(b) Fuse wire
(c) Filament
(d) Connecting wire
11. An electromagnet behaves like a magnet only when:
(a) It is placed near a magnet
(b) Electric current flows through it
(c) It is heated
(d) It is made of steel
12. Which of the following does NOT use the heating effect of current?
(a) Electric kettle
(b) Electric bell
(c) Electric toaster
(d) Geyser
13. MCB stands for:
(a) Miniature Circuit Breaker
(b) Maximum Current Breaker
(c) Minimum Circuit Board
(d) Main Circuit Battery
14. When an electric current flows through a wire, the wire:
(a) Becomes cold
(b) Becomes a conductor
(c) Becomes hot
(d) Changes color
15. Which of the following is a source of electric current?
(a) Bulb
(b) Key
(c) Battery
(d) Wire
16. In an electric bell, which component acts as an electromagnet?
(a) The hammer
(b) The gong
(c) The coil of wire wound on an iron core
(d) The contact screw
17. If a fuse blows frequently in a house, it indicates:
(a) There is a short circuit or overloading
(b) The voltage is too low
(c) The bulbs are fused
(d) The switch is broken
18. The magnetic effect of current can be demonstrated using a:
(a) Thermometer
(b) Compass needle
(c) Barometer
(d) Torch bulb
19. To make a battery of 4 cells, the positive terminal of one cell must be connected to:
(a) Positive terminal of the next cell
(b) Negative terminal of the next cell
(c) Any terminal
(d) The switch
20. Electromagnets are used in:
(a) Electric fans
(b) Cranes to lift heavy iron loads
(c) Electric bells
(d) All of the above
Answer Key
1 — (a) 2 — (b) 3 — (b) 4 — (b) 5 — (c) 6 — (b) 7 — (b) 8 — (b) 9 — (c) 10 — (c) 11 — (b) 12 — (b) 13 — (a) 14 — (c) 15 — (c) 16 — (c) 17 — (a) 18 — (b) 19 — (b) 20 — (d)