Students can use Class 7 Science Curiosity Extra Questions and Chapter 3 Electricity Circuits and Their Components Extra Question Answer to prepare effectively at home.
Class 7 Science Chapter 3 Electricity Circuits and Their Components Extra Questions
Class 7 Science Chapter 3 Extra Questions on Electricity Circuits and Their Components
Electricity Circuits and Their Components Class 7 Very Short Question Answer
Question 1.
Name an insulator made of wood.
Answer:
Stick.
Question 2.
Is key made up of metal is a good conductor of electricity.
Answer:
Yes.
Question 3.
Why wires are covered with plastic?
Answer:
The plastic is electrical insulator.
Question 4.
Name some components of a simple electric circuit.
Answer:
Battery, wire, key and bulb are the components of a simple electric circuit.
Question 5.
Electric lamps are of two types. Name them.
Answer:
(a) LED lamp (b) Incandescent lamp.
Question 6.
Why wires made of copper are used in electric cisuits?
Answer:
Copper is a good conductor of electricity and a less costly metal.
Question 7.
Does the bulb glow when the circuit is open?
Answer:
No, the bulb does not glow if circuit is open.
Question 8.
What is direction of electric current in an electric circuit?
Answer:
Positive to the negative terminal of an electric cell.
Question 9.
Draw symbol for an electric lamp.
Answer:
Question 10.
What type of electricity is used in homes and industries?
Answer:
Alternating Current (AC)
Question 11.
What happens if the filament in an incandescent lamp breaks?
Answer:
The lamp stops glowing because the circuit is broken.
Question 12.
Which component of a torchlight is powered by the battery to provide light?
Answer:
LED or Incandescent lamp.
Question 13.
The safety pin touches two drawing pins to close gaps, to complete path and permit the current to flow. What do you call this position?
Answer:
“ON” Position.
Question 14.
Name a device that completes or breaks the circuit. What do you use for lights?
Answer:
Switches of different designs.
Question 15.
What happens when an electric cell is connected to a circuit?
Answer:
It supplies electrical energy to the circuit.
Electricity Circuits and Their Components Class 7 Short Question Answer
Question 1.
Define a circuit diagram.
Answer:
It is defined “as a representation of electrical circuit by use of symbols”.
Question 2.
Distinguish between Incandescent lamp and LED lamp.
Answer:
Following are the difference
| Incandescent Lamp | LED Lamp |
| 1. It has a filament. | 1. It does not have a filament. |
| 2. Torchlight is used in these lamps. | 2. A torch can use one or more LED’s. |
Question 3.
Draw a circuit diagram for LED lamp.
Answer:
Question 4.
Compare a scale to a key in reference to good or bad conductors of electricity.
Answer:
Difference between a scale and a key:
| A Scale | А Кеу |
| 1. Made of wood/plastic. | 1. Made of metal. |
| 2. Insulator of electricity. | 2. Conductor of electricity. |
Question 5.
Differentiate between Conductors and Insulators of electricity.
Answer:
The difference are:
| Conductor | Insulator |
| 1. Good conductor of electricity. | 1. Poor conductor of electricity. |
| 2. e.g., ceramics | 2. e.g., plug tops. |
Question 6.
(a) Name portable source of electrical energy.
(b) Two terminals of an electric cell are. Name them.
Answer:
(a) Electrice cell.
(b) positive and negative terminals.
Question 7.
Draw a circuit diagram of an electrical circuit with an incandescent lamp.
Answer:
Question 8.
Explain an electrical circuit with the help of a diagram.
Answer:
This shows a complete path of electric current to flow through a lamp. When current passes through a circuit, the lamp glows then. This makes an electrical circuit one terminal of an electric cell is united to the other terminal of a lamp. See figure.
Question 9.
Expand the following :
(a) IEC
(b) IEEE
Answer:
(a) IEC: International Electro-chemical Commission.
(b) IEEE: Institute of Electrical and Electronics Engineers.
Question 10.
How can we connect the cells to prepare a battery?
Answer:
The positive terminal of one cell is connected to the negative terminal of the next cell to prepare a battery.
Question 11.
Draw the symbol of an electric bulb in an electric circuit.
Answer:
Question 12.
How do you make an electric lamp glow by using an electric cell?
Answer:
(a) Take four lengths of a wire, a torch, lamp, an electric cell and a cell holder. Then remove plastic cover app. 1 cm but both ends of each wire must be clear. Now, unite two wires to two ends of the cell holder.
(b) Insert cell into holder, -ve terminal lies on spring side.
(c) Two wires to screws of lamp holder are not attached. In holder, fix the lamp then (turn it around in a holder). After all you unite a cell to lamp for glowing.
Question 13.
Draw a figure of an LED lamp for a torch.
Answer:
Question 14.
Construct LED’s for different colours. Does LED has filaments ? Explain shortly.
Answer:
See figure as given below of LED’s.
The LED’s do not have filaments but possess two terminals (+ve and -ve); +ve remain united to -ve one.
Question 15.
Explain the construction of a battery.
Answer:
A battery is a combination of two or more cells.
It is constructed by placing the cells properly in a cell holder so that the positive terminal of one cell is connected to the negative terminal of the next cell. A metal wire is then connected to each of the two metal.
Question 16.
(a) Draw circuit diagrams of a cell and an LED.
(b) Draw circuit figures with an incandescent lamp and an LED lamp.
Answer:
(a) See figure
(b) See figure
Question 17.
Construct figures of conduction tester and the use of it to test a material.
Answer:
See following figure as in Q.no. 5 LA type.
Question 18.
Prepare a list of five insulators as well as conductors of electricity. Name object, material it made of and write conclusion (whether conductor or insulator).
Answer:
List of Insulators/Conductors (five) :
| S. No. | Object | Material | Conclusion |
| 1. | Eraser | Rubber | Insulator |
| 2. | Key | Metal | Conductor |
| 3. | Candle | Wax | Insulator |
| 4. | Scale | Plastic | Insulator |
| 5. | Stick | Wood | Insulator |
Question 19.
Compare good conductors and poor conductors of electricity by giving examples of each. (V.Imp.)
Answer:
The comparison are :
| Good Conductors | Poor Conductors |
| 1. These are materials by which electricity may flow. | 1. Materials by which electric current does not flow. |
| 2. These are good conductors of electric current. | 2. They are bad conductors of electricity. |
| 3. Examples are copper, silver. | 3. Examples are candle made of wax and eraser made by rubber. |
| 4. Socket is made of wires/conductors to protect people. | 4. Plastic insulator protect us from electric shock at all. |
Question 20.
Draw a well-labelled diagram of small incandescent lamp that may be used in a torch.
Answer:
See figure :
Question 21.
Why should we not touch the lighted bulb?
Answer:
We should never touch a lighted electric bulb connected to the mains because it may be very hot, and touching it could result in serious burns. Similarly, we should avoid experimenting with electrical supplies from the mains, a generator, or an inverter, as they may cause an electric shock.
Question 22.
Draw the symbols of the following circuit components.
(i) electric cell
Answer:
(ii) Switch in ‘OFF’ position
Answer:
(iii) electric bulb
Answer:
(iv) battery
Answer:
Electricity Circuits and Their Components Class 7 Long Question Answer
Question 1
Define electric circuit with the help of diagram.
Answer:
A simple electrical circuit is shown by an electric cell. See figure an electric cell has ‘+ve’ and ‘-ve’ terminals as shown by marks on a cell. Electric cell possesses two terminals – one is ‘+ve’ and other is -ve. Positive terminal is a metal cap. But metal disc shows ‘-ve’ terminal of electric cell at all. The portable source of electrical energy is shown by an electric cell now-a-days.
Question 2.
Show a battery of two cells as well as a battery of 4 cells. Now cells one united in a battery. (Imp.)
Answer:
Battery: A battery is a device formed by connecting two or more cells together. To form a battery, the cells are placed in a cell holder so that the positive terminal of one cell is connected to the negative terminal of the next cell, and so on. A metal wire is connected to each of the two metal clips on the cell holder.
Question 3.
Define a circuit diagram. Write electric components and draw their symbols.
Answer:
See circuit diagrams given below as :
Question 4.
Construct circuit figure to show switch on and switch off positions by symbols.
Answer:
Switch on, switch off positions and symbols. See figure :
Question 5.
Connect a lamp to an electric cell. Leave the two ends of wires un-united. Use a conduction tester for testing a material. Show these by diagrams. Write procedure.
Answer:
Lamp, Electric cell and A Tester : Procedure : Connect a lamp to an electric cell. Leave 2 ends of connection open. Use a tester say metal spoon to test the material through which current passes.
Electricity Circuits and Their Components Class 7 Case Based Questions
1. Read the following passage carefully and answer the questions that follow :
We use fuse to check electric current. To save electric appliances to get damaged from excessive flow of electric current. We use a safety device. It is known as fuse. It prevents big amount of current from flowing in a device appliance since it cuts off supply of electricity, hence prevents damage. It has a wire made of material. That melts easily if heated. It breaks a circuit hence stops flow of current in a circuit.
(i) Device used to prevents flow of excessive current in the circuit is known as :
(a) fuse
(b) bulb
(c) switch
(d) None of these
Answer:
(a) fuse
(ii) The lamp is fused. The reason is a broken :
(a) lamp
(b) filament
(c) wire
(d) current flow
Answer:
(b) filaments
2. Read the following passage carefully and answer the questions that follow :
In a classroom activity, students were given wires, a bulb, a switch, and a cell. They connected the components to form a circuit, but the bulb didn’t glow. They examined the setup and discovered that one of the wires was broken. After replacing it, the bulb glowed brightly. Their teacher asked questions about the flow of current, the role of conductors, and why a complete path is needed.
(i) What is the most likely reason the bulb did not glow initially?
(a) The bulb was faulty
(b) The cell was too weak
(c) The wire was broken
(d) The switch was open
Answer:
(c) The wire was broken
(ii) What is required for an electric current to flow in a circuit?
(a) A plastic wire
(b) An open switch
(c) A complete and closed path
(d) A glowing bulb
Answer:
(c) A complete and closed path
(iii) What is the function of a switch in an electric circuit?
(a) To control the brightness of the bulb
(b) To increase the voltage
(c) To open or close the circuit
(d) To connect the bulb to the wire
Answer:
(c) To open or close the circuit
(iv) Which of the following materials would best replace the broken wire?
(a) Cotton thread
(b) Rubber strip
(c) Copper wire
(d) Plastic tube
Answer:
(c) Copper wire
Electricity Circuits and Their Components Class 7 Picture Based Questions
I. Observe the picture and answer the questions :
Question 1.
The circuit must be closed to:
(a) cell to operate
(b) glow bulb
(c) stop circuit
(d) current to glow
Answer:
(d) current to glow
Question 2.
Bulb will glow only when current is flowing through
(a) circuit
(b) battery
(c) cells
(d) bulb
Answer:
(a) circuit
Question 3.
What is thin wire called and when it glows?
Answer:
A thin wire is called a filament and it glows when electric current passes through it.
II. Observe the picture and answer the following questions :
Question 1.
What does the above given image show?
(a) An electric cell
(b) A battery
(c) A power house
(d) None of these
Answer:
(a) An electric cell
Question 2.
What is the terminal marked with a “+” sign called?
(a) Negative terminal
(b) Positive terminal
(c) Both of these
(d) None of these
Answer:
(b) Positive terminal
Question 3.
Which terminal of the cell does the electric current flow from?
(a) Positive terminal
(b) Negative terminal
(c) Only (b) is correct
(d) None of these
Answer:
(a) Positive terminal
Question 4.
What is the function of the positive and negative terminals in an electric cell?
Answer:
The positive and negative terminal in an electric cell help to create path for flow of current.
Electricity Circuits and Their Components Extra Questions for Practice
Multiple Choice Questions (MCQs):
Question 1.
Electricity is used in :
(a) lighting
(b) transportation
(c) cooking
(d) all of these
Question 2.
A simple circuit is represented by :
(a) Electric cell
(b) Insulators
(c) Conductors
(d) None of these
Question 3.
An incandescent lamp does not glow even it remain united to a cell :
(a) Lamp is fused
(b) Filament of lamp is broken
(c) Flow of current is stopped
(d) All of the above
Question 4.
Which is used to test electrical experiments?
(a) Cells
(b) Wall clocks
(c) Batteries
(d) All of these
Very Short Answer Type Questions:
Question 1.
What is torchlight?
Question 2.
Draw symbol for an electric cell.
Question 3.
What is meant by “circuit is open”?
Question 4.
What does the two lines represent in a symbol of electric cell?
Short Answer Type Questions:
Question 1.
Name any three poor conductors of electricity.
Question 2.
Name any three good conductors of the electricity.
Question 3.
Draw a closed circuit.
Question 4.
State three symbols each for (i) electric lamp, (ii) an LED, (iii) a battery.
Question 5.
Draw a diagram to show an electric lamp.
Question 6.
Draw an Electrical Circuit.
Question 7.
Write short notes on :
(a) battery
(b) fuse
(c) switch
Question 8.
How will you use a conduction tester to test a material like a steel spoon?
Long Answer Type Questions :
Question 1.
Insulators protect us from electric shocks. How?
Question 2.
Why should we handle electrical appliances with care? Explain briefly.
Question 3.
How would you make a torch lamp to glow by using a battery?
Question 4.
Write explanatory notes on :
(a) A Torchlight
(b) An Electric cell
(c) A Battery
(d) An LED