Important Questions Class 7 Science Chapter 3: Electricity, Circuits and Their Components

Electricity is a form of energy used to run devices for lighting, communication, heating, cooling, transport and work.
Important Questions Class 7 Science Chapter 3 help students revise cells, batteries, circuits, switches, LEDs, conductors and insulators.

Electricity is used in homes, schools, hospitals, factories, streets, trains, lifts, computers and mobile phones. Class 7 Science Chapter 3 explains how electric current flows through a complete circuit and makes a lamp or LED glow. Students learn about electric cells, batteries, terminals, incandescent lamps, LED lamps, switches, circuit diagrams, conductors and insulators. The chapter also teaches safety by warning students to use only cells or batteries for experiments. These questions are useful for the 2026-27 exam because they combine definitions, circuit reasoning, observation-based answers and application questions.

Key Takeaways

• Electric Cell: An electric cell is a portable source of electrical energy.
• Battery: A battery is a combination of two or more cells connected together.
• Closed Circuit: A lamp glows only when the circuit forms a complete path for current.
• Conductors: Metals allow electric current to flow easily and are used for wires.

Important Questions Class 7 Science Chapter 3 Structure 2026-27

Objective Type Questions from Important Questions Class 7 Science Chapter 3

Objective questions from this chapter usually test circuit components, terminals, LED direction, switch positions and conductors. Students should learn the exact function of each part.

Q1. An electric cell is a:

1. Source of sound energy
   b. Portable source of electrical energy
   c. Type of switch
   d. Type of wire covering

Answer: b. Portable source of electrical energy

An electric cell provides electrical energy to small devices.

Q2. An electric cell has:

1. One terminal
   b. Two terminals
   c. Three terminals
   d. No terminal

Answer: b. Two terminals

An electric cell has one positive terminal and one negative terminal.

Q3. The metal cap of an electric cell is the:

1. Negative terminal
   b. Positive terminal
   c. Insulator
   d. Filament

Answer: b. Positive terminal

The metal cap is marked with the positive sign.

Q4. The flat metal disc of an electric cell is the:

1. Positive terminal
   b. Negative terminal
   c. Switch
   d. Lamp holder

Answer: b. Negative terminal

The flat metal disc is the negative terminal.

Q5. A combination of two or more cells is called a:

1. Circuit diagram
   b. Battery
   c. Filament
   d. Conductor

Answer: b. Battery

In a battery, cells are usually connected positive to negative.

Q6. In an incandescent lamp, the thin wire that glows is called:

1. Terminal
   b. Filament
   c. Switch
   d. Insulator

Answer: b. Filament

The filament gets hot and glows when current passes through it.

Q7. An LED differs from an incandescent lamp because it:

1. Has no terminals
   b. Has no filament
   c. Does not need current
   d. Works without a circuit

Answer: b. Has no filament

An LED glows without a filament.

Q8. The longer wire of an LED is usually the:

1. Negative terminal
   b. Positive terminal
   c. Broken terminal
   d. Insulator

Answer: b. Positive terminal

The longer wire of an LED is connected to the positive terminal.

Q9. An LED glows only when:

1. It is connected in the correct direction
   b. Its terminals are reversed
   c. The circuit is open
   d. No current flows

Answer: a. It is connected in the correct direction

Current can pass through an LED in one direction only.

Q10. An electrical circuit provides:

1. A complete path for current
   b. A broken path for current
   c. Only a diagram
   d. Only a switch

Answer: a. A complete path for current

A complete circuit allows electric current to flow.

Q11. The direction of electric current in a circuit is taken from:

1. Negative to positive terminal
   b. Positive to negative terminal
   c. Switch to air
   d. Lamp to battery only

Answer: b. Positive to negative terminal

In a closed circuit, current direction is taken from the positive to the negative terminal of the cell.

Q12. A switch in the ON position:

1. Breaks the circuit
   b. Completes the circuit
   c. Removes the cell
   d. Acts as an insulator only

Answer: b. Completes the circuit

The ON position allows current to flow.

Q13. A switch in the OFF position:

1. Completes the circuit
   b. Creates a gap in the circuit
   c. Makes the lamp brighter
   d. Increases current

Answer: b. Creates a gap in the circuit

An open circuit does not allow current to flow.

Q14. Which material is a conductor of electricity?

1. Plastic
   b. Rubber
   c. Copper
   d. Wax

Answer: c. Copper

Copper is a metal and allows current to flow easily.

Q15. Which material is an insulator?

1. Silver
   b. Copper
   c. Gold
   d. Rubber

Answer: d. Rubber

Rubber does not allow electric current to pass easily.

Very Short Answer Questions from Class 7 Science Chapter 3 Important Questions

Very short answers from this chapter usually ask for definitions and direct reasons. Write the term first, then add one clear fact.

Q16. What is an electric cell class 7?

An electric cell class 7 means a portable source of electrical energy. It has two terminals: a positive terminal and a negative terminal.

Q17. What is a battery class 7 science?

A battery class 7 science answer should mention two or more cells. A battery is a combination of two or more cells connected together, usually with the positive terminal of one cell connected to the negative terminal of the next cell.

Q18. What is an electrical circuit class 7?

An electrical circuit class 7 means a complete path through which electric current can flow. A lamp glows only when the circuit is complete.

Q19. What is a filament class 7 science?

A filament class 7 science term means the thin wire inside an incandescent lamp. It gets hot and glows when electric current passes through it.

Q20. What is an LED class 7 science?

An LED class 7 science answer should mention Light Emitting Diode. An LED is a lamp that has two terminals and glows only when connected in the correct direction.

Q21. What is an electric switch class 7?

An electric switch class 7 means a simple device that completes or breaks an electric circuit. It allows us to turn a device ON or OFF.

Q22. What is a circuit diagram class 7 science?

A circuit diagram class 7 science answer should mention symbols. A circuit diagram is a representation of an electrical circuit using standard symbols for components.

Short Answer Questions from Electricity Circuits and Their Components Class 7 Important Questions

Short answer questions from this chapter usually test how components work. Use examples from torchlight, cell, lamp, LED and switch.

Q23. Why does a torch lamp glow in one switch position but not in the other?

A torch lamp glows when the switch completes the circuit.

In the ON position, the switch provides a complete path for current to flow from the cell through the lamp. In the OFF position, the switch creates a gap in the circuit.

So, current does not flow and the lamp does not glow.

Q24. How are cells connected to make a battery?

Cells are connected by joining the positive terminal of one cell to the negative terminal of the next cell.

This arrangement forms a battery. Devices like torches often use more than one cell because more cells can provide energy for a longer time or more energy to the circuit.

Q25. Why does an incandescent lamp glow?

An incandescent lamp glows because electric current passes through its filament.

The filament is a thin wire inside the glass bulb. When current flows through it, the filament gets hot and produces light.

If the filament breaks, the lamp becomes fused and does not glow.

Q26. Why does an LED not glow when its terminals are reversed?

An LED does not glow when its terminals are reversed because current can pass through it in only one direction.

The longer wire of the LED is the positive terminal. It must be connected to the positive terminal of the battery. The shorter wire must be connected to the negative terminal.

When reversed, current does not pass through the LED.

Q27. What is the difference between an open circuit and a closed circuit?

A closed circuit has a complete path for electric current.

In a closed circuit, the switch is ON and the lamp can glow. An open circuit has a gap in the path. In an open circuit, the switch is OFF and current cannot flow.

So, devices work only in a closed circuit.

Q28. Why are circuit diagrams useful?

Circuit diagrams are useful because they show electrical circuits in a simple form.

Instead of drawing real components, we use symbols for cells, batteries, lamps, LEDs, wires and switches. This makes circuits easier to draw, read and compare.

Standard symbols also help people understand circuits clearly.

Q29. Why are metals used for making electric wires?

Metals are used for making electric wires because they are good conductors of electricity.

Electric current can flow easily through metals. Copper is commonly used because it conducts electricity well and is available at a lower cost than silver or gold.

Q30. Why are electric wires covered with plastic or rubber?

Electric wires are covered with plastic or rubber because these materials are insulators.

Insulators do not allow electric current to pass through them easily. This covering protects people from electric shocks and prevents accidental contact with conducting wires.

Long Answer Questions from Important Questions Class 7 Science Chapter 3

Long answer questions from this chapter often ask students to explain a circuit, compare components or describe an activity. Use correct terms and safety points.

Q31. Explain the working of a simple electrical circuit with a cell and a lamp.

A simple electrical circuit has an electric cell, connecting wires and a lamp.

The cell supplies electrical energy. It has a positive terminal and a negative terminal. The wires connect one terminal of the cell to one terminal of the lamp and the other terminal of the lamp to the other terminal of the cell.

When the path is complete, electric current flows through the circuit. Current passes through the filament of the incandescent lamp. The filament gets hot and glows.

If the path is broken anywhere, current stops flowing. The lamp does not glow in an open circuit.

Q32. Explain how a switch works in an electric circuit.

A switch controls the flow of electric current by completing or breaking the circuit.

In the ON position, the switch closes the gap in the circuit. This gives current a complete path to flow through the cell, wires and lamp. The lamp glows.

In the OFF position, the switch creates a gap in the circuit. Current cannot flow through an incomplete path. The lamp does not glow.

A switch can be placed anywhere in a circuit because its main function is to complete or break the current path.

Q33. Compare incandescent lamps and LED lamps.

Both lamps need a complete circuit to glow.

Q34. Explain conductors and insulators with examples.

Conductors are materials through which electric current can pass easily.

Metals like copper, silver, gold, aluminium, iron and steel are conductors. Wires, plug connectors and sockets are made using conductors.

Insulators are materials through which electric current cannot pass easily.

Plastic, rubber, glass, wax, wood and ceramics are insulators. They are used to cover wires, switches and plug tops.

Both conductors and insulators are important for safe electrical use.

Q35. Describe an activity to test whether a material is a conductor or insulator.

Take an electric cell, a lamp and connecting wires.

Leave two wire ends free in the circuit. Touch the two free ends together once to check whether the lamp glows. If it glows, the tester is ready.

Now place an object between the two free wire ends. If the lamp glows, the material allows current to pass. It is a conductor.

If the lamp does not glow, current does not pass through the material. It is an insulator.

This activity can test objects like keys, coins, plastic scales, paper, rubber, wood and aluminium foil.

Case-Based Questions from Class 7 Science Electricity Important Questions

Case-based questions from this chapter usually give a circuit situation. Identify whether the circuit is complete and whether the component is connected correctly.

Q36. Case Study: Torchlight Does Not Glow

Nihal opens a torchlight and finds two cells, a switch and a lamp. The lamp does not glow even after the switch is pushed to the ON position.

Q36(a). What is one possible reason?

One possible reason is that the cells are not placed in the correct order.

The positive terminal of one cell should connect to the negative terminal of the next cell.

Q36(b). What can happen if the lamp filament is broken?

The lamp will not glow.

A broken filament stops current from flowing through the lamp.

Q36(c). What should Nihal check in the switch?

Nihal should check whether the switch completes the circuit in the ON position.

If there is still a gap, current cannot flow.

Q36(d). What safety rule should he follow?

He should use only cells or batteries for this activity.

He should never experiment with the main power supply at home or school.

Q37. Case Study: LED Connected to a Battery

A student connects an LED to a two-cell battery. The LED does not glow. The teacher asks the student to check the LED terminals.

Q37(a). Which LED terminal should connect to the positive terminal of the battery?

The longer wire of the LED should connect to the positive terminal of the battery.

This is the positive terminal of the LED.

Q37(b). Which LED terminal should connect to the negative terminal?

The shorter wire of the LED should connect to the negative terminal of the battery.

This completes the correct direction for current through the LED.

Q37(c). Why did the LED not glow earlier?

The LED may have been connected in the wrong direction.

Current passes through an LED in one direction only.

Q37(d). Does an LED have a filament?

No, an LED does not have a filament.

It is different from an incandescent lamp.

Q38. Case Study: Testing Classroom Objects

A class uses a simple tester to check a key, a rubber eraser, a coin, a plastic scale and aluminium foil.

Q38(a). Which objects are likely to make the lamp glow?

The key, coin and aluminium foil are likely to make the lamp glow.

They are made of metals and conduct electricity.

Q38(b). Which objects are likely to stop the lamp from glowing?

The rubber eraser and plastic scale are likely to stop the lamp from glowing.

They are insulators.

Q38(c). What conclusion can students draw about metals?

Students can conclude that metals are good conductors of electricity.

That is why metals are used in electrical wires and connectors.

Q38(d). Why are insulators useful?

Insulators protect people from electric shock.

They are used to cover wires, switches and plug tops.

Diagram-Based Questions from Electrical Circuit Class 7

Diagram-based questions usually ask students to draw symbols or explain why a circuit works. Use labelled symbols and show a complete path.

Q39. Draw a circuit diagram for a simple torch using symbols.

A simple torch circuit should include:

1. Battery
2. Switch
3. Lamp
4. Connecting wires

In the diagram, the battery connects to the switch. The switch connects to the lamp. The lamp connects back to the battery. The lamp glows only when the switch is ON and the circuit is closed.

Q40. Draw a circuit diagram using an electric cell, lamp and switch in ON position.

The circuit diagram should show one electric cell, one lamp, one switch and wires.

The switch should be shown closed in the ON position. The wires should connect the positive terminal of the cell to the switch, then to the lamp, and back to the negative terminal of the cell.

This is a closed circuit, so the lamp glows.

Q41. What do the long and short lines in the symbol of an electric cell show?

The long line represents the positive terminal of the electric cell.

The short line represents the negative terminal of the electric cell.

This helps identify the correct direction of current in the circuit diagram.

Q42. What does the symbol of an LED show?

The LED symbol shows the direction in which current can flow.

The arrows in the symbol show that the LED emits light. The LED must be connected in the correct direction to glow.

Safety and Application Questions from Conductors and Insulators Class 7

Safety questions from this chapter connect electricity with daily life. Mention the reason clearly because safety depends on correct habits.

Q43. Why should we never experiment with the main power supply?

We should never experiment with the main power supply because it can be dangerous.

Electricity from sockets, electric poles and generators can cause severe injury or death. Students should use only cells or batteries for experiments.

Q44. Why should we avoid touching switches with wet hands?

We should avoid touching switches with wet hands because water can make electric shock more dangerous.

The human body is a conductor of electricity. Wet hands increase the risk of current passing through the body.

Q45. Why are conductors and insulators both important in electrical devices?

Conductors allow current to flow where it is needed.

Insulators stop current from passing where it can be dangerous. For example, copper inside a wire conducts current, while plastic covering protects people from shocks.

Both materials make electrical devices useful and safe.

Chapter-Wise Revision for Important Questions Class 7 Science Chapter 3

Important questions class 7 science chapter 3 should be revised in five parts: cell, circuit, lamp, switch and materials.

Start with electric cell class 7. Learn positive terminal, negative terminal and how cells form a battery.

Next, revise electrical circuit class 7. A complete circuit is needed for current to flow and make a lamp glow.

Then revise LED class 7 science and filament class 7 science. Remember that an incandescent lamp has a filament, while an LED has positive and negative terminals.

After that, revise electric switch class 7. A switch completes or breaks a circuit.

Finally, revise conductors and insulators class 7. Metals conduct electricity, while plastic, rubber and ceramics act as insulators.

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