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CBSE · Class 7 · Science

Electricity: Circuits and their Components

Standard difficulty · 20 questions · 40 marks

Name: Date: Score: ____ / 40

Show your working for Sections B and C. Answers are on the last page — try every question first!

Section A — Choose the correct answer8 × 1 = 8 marks
1.
A cell has a positive terminal which is the:
  1. paper cover
  2. middle of the cell
  3. flat metal disc
  4. metal cap
2.
Which of these is a CONDUCTOR of electricity?
  1. a copper wire
  2. a paper strip
  3. a cork
  4. a candle
3.
Which of these is an INSULATOR?
  1. a safety pin
  2. a copper wire
  3. a steel spoon
  4. a cork
4.
In which case will the lamp glow?
  1. when an LED is joined the wrong way round
  2. when the cell is used up
  3. when the switch is OFF
  4. when the switch is ON and all parts are working
5.
In a circuit diagram, a circle with a cross or loop inside stands for a:
  1. lamp
  2. switch ON
  3. LED
  4. battery
6.
Each torch needs a battery of 3 cells. How many cells are needed for 15 torches?
  1. 15 cells
  2. 18 cells
  3. 48 cells
  4. 45 cells
7.
A cell costs ₹12. How much do 10 cells cost?
  1. ₹120
  2. ₹108
  3. ₹22
  4. ₹132
8.
8 lamps were tested in a circuit. 6 did not glow because their filaments were broken. How many lamps were fine?
  1. 14 lamps
  2. 6 lamps
  3. 2 lamps
  4. 8 lamps
Section B — Short answer8 × 2 = 16 marks
9.
What is an electric circuit?
10.
Write "conductor" or "insulator": (a) a coin (b) a plastic ruler
11.
Will the lamp glow? Write "yes" or "no": (a) when a wire's plastic covering was not removed at the joint (b) when the switch is OFF
12.
Name the component: (a) a gap in the line that is closed (b) a gap in the line that is open
13.
Is each "positive" or "negative"? (a) the long line in a cell symbol (b) the flat metal disc of a cell
14.
A box has 5 batteries of 2 cells each and 5 loose cells. How many cells are there in all?
15.
A circuit needs 6 pieces of copper wire, each 100 cm long. How many centimetres of wire is that? How many metres?
16.
Where is each used in electrical things, and why? (a) ceramic (b) aluminium
Section C — Word problems4 × 4 = 16 marks
17.
Describe how to make a conduction tester and use it to test materials.
18.
You test a paper strip, a steel spoon, a cork, aluminium foil, a safety pin, a glass marble with a conduction tester. (a) Which will make the lamp glow? (b) Which will not? (c) Why must wire joints be stripped of their covering?
19.
Will the lamp glow in each case? Give a reason for each: (1) a plastic clip is used to close the switch gap; (2) the switch is OFF; (3) a wire's plastic covering was not removed at the joint; (4) the cell is used up.
20.
A class has 5 cells and does not know which work. They test each in a circuit with a lamp and find 2 do not light it. (a) How many cells work? (b) Describe the test. (c) Why must the lamp and wires stay the same for every cell?
AmbifulWorksheets
Practice that never repeats
CBSE · Class 7 · Science

Answer key

Electricity: Circuits and their Components · AW-7S-ELC-2026-V1 · For parents — fold back or tear off before handing the sheet to your child.

QAnswerWorking
1(d) metal capthe flat disc is negative
2(a) a copper wire—
3(d) a cork—
4(d) when the switch is ON and all parts are working—
5(a) lamp—
6(d) 45 cells15 × 3 = 45
7(a) ₹12012 × 10 = 120
8(c) 2 lamps8 − 6 = 2
9A complete, closed path through which electric current flows.—
10(a) conductor (b) insulator—
11(a) no (b) no—
12(a) switch ON (b) switch OFF—
13(a) positive (b) negative—
1415 cells5 × 2 + 5
15600 cm; 6 m6 × 100
16(a) lamp holders: an insulator that does not melt (b) overhead power lines: light and a good conductor—
17Connect a cell, a lamp (or LED) and wires so two free wire ends are left open. Touch both ends to an object. If the lamp glows, the object is a conductor (key, coin, foil); if not, it is an insulator (wood, plastic, rubber).—
18(a) a steel spoon, aluminium foil, a safety pin (b) a paper strip, a cork, a glass marble (c) The plastic covering is an insulator; current flows only through bare metal touching bare metal.—
19(1) no; (2) no; (3) no; (4) no. A lamp glows only if the circuit is complete, the cell works and an LED faces the right way.—
20(a) 3 cells (b) Put each cell in turn in a closed circuit with the same lamp; if the lamp glows, the cell works. (c) So that only the cell changes; otherwise a faulty lamp or wire could give a wrong result.—