1. Decide amongst the options a, b, c, and d listed in fig. 12.1, which depicts the proper present orientation.
1. Decide amongst the options a, b, c, and d listed in fig. 12.1, which depicts the proper present orientation.
Explanation:
(b) In an electrical circuit, current travels in the opposite direction, from the positive to the negative terminal of an electric cell.
2. Choose the false statement.
(A) The source of current in a circuit is a switch.
(a) A switch facilitates closing or opening the circuit.
(c) A switch enables us to use electricity in accordance with our needs.
(d) The switch has an air gap between its terminals when it is open.
2. Choose the false statement.
(A) The source of current in a circuit is a switch.
(a) A switch facilitates closing or opening the circuit.
(c) A switch enables us to use electricity in accordance with our needs.
(d) The switch has an air gap between its terminals when it is open.
Explanation:
(a) The source of electrical current in a circuit is a switch.
Electric current in a circuit is generated by electric cells, not switches.
3. Light is created in an electric bulb by the lighting of
(a) the glass bulb case
(b) the thin filament
(c) the thick wires supporting the filament
(d) gases within the glass bulb case.
3. Light is created in an electric bulb by the lighting of
(a) the glass bulb case
(b) the thin filament
(c) the thick wires supporting the filament
(d) gases within the glass bulb case.
Explanation:
The thin filament is in (b).
4. If the ends A and B are joined with the following arrangement in fig. 12.2, the bulb will not glow
(a) A metal clip
(b) a steel spoon
(c) a plastic clip
(d) an iron wire
4. If the ends A and B are joined with the following arrangement in fig. 12.2, the bulb will not glow
(a) A metal clip
(b) a steel spoon
(c) a plastic clip
(d) an iron wire
Explanation:
(c) A clip made of plastic.
Polypropylene clips are insulators and have low electrical conductivity.
5. When the switch is flipped to the "ON" position in the circuit seen in Figure 12.3,
(a) Bulb A will shine first,
(b) Bulb B will glow first,
(c) Bulb C will glow first, and
(d) All Bulbs Will Glow At The Same Time.
5. When the switch is flipped to the "ON" position in the circuit seen in Figure 12.3,
(a) Bulb A will shine first,
(b) Bulb B will glow first,
(c) Bulb C will glow first, and
(d) All Bulbs Will Glow At The Same Time.
Explanation:
(d): Every light will be illuminated.
After the circuit is finished, the current is immediately detected at every point in the circuit.
6. The torch bulb's filament consists of
(a) a metal case,
(b) a metal tip in the middle of the base,
(c) two hefty wires, and
(d) a thin wire.
6. The torch bulb's filament consists of
(a) a metal case,
(b) a metal tip in the middle of the base,
(c) two hefty wires, and
(d) a thin wire.
Explanation:
A thin wire is (d).
7. There aren't enough connection wires for Paheli. She may use or a thick piece of thread to complete an electrical circuit.
(a) a glass bangle
(b)thick thread
(c) rubber pipe
(d) steel spoon , or a thick piece of thread to complete an electrical circuit.
7. There aren't enough connection wires for Paheli. She may use or a thick piece of thread to complete an electrical circuit.
(a) a glass bangle
(b)thick thread
(c) rubber pipe
(d) steel spoon , or a thick piece of thread to complete an electrical circuit.
Explanation:
Steel spoon (d)
A steel spoon will conduct electricity well. As a result, we complete an electrical circuit using a steel spoon.
8. . Which of the circuits A, B, and C listed in fig. 12.4 will use up the cell very quickly?
8. . Which of the circuits A, B, and C listed in fig. 12.4 will use up the cell very quickly?
Explanation:
The cell will be completely depleted in circuit A.
9. A bulb is depicted in Fig. 12.5 with its various components labelled 1, 2, 3, 4, and 5. Which of them has the bulb's terminals labelled?
9. A bulb is depicted in Fig. 12.5 with its various components labelled 1, 2, 3, 4, and 5. Which of them has the bulb's terminals labelled?
Explanation:
The terminals of the bulb are identified by labels 3 and 4.
10. A lamp, a cell, a switch, and some connecting cables are given to you. Make a schematic to demonstrate how they are connected to light the bulb.
10. A lamp, a cell, a switch, and some connecting cables are given to you. Make a schematic to demonstrate how they are connected to light the bulb.
Explanation:
11. In the circuit depicted in fig. 12.6 will the light glow? Explain.
11. In the circuit depicted in fig. 12.6 will the light glow? Explain.
Explanation:
The switch is open, and the circuit is broken, thus the bulb won't light up in this circuit. Only a closed circuit may carry current.
12. As seen in fig. 12.7, a switch connects an electric light to a cell. The bulb does not glow when the switch is turned to the "ON" position. What might be the cause or causes of it? Choose any two of them to mention.
12. As seen in fig. 12.7, a switch connects an electric light to a cell. The bulb does not glow when the switch is turned to the "ON" position. What might be the cause or causes of it? Choose any two of them to mention.
Explanation:
The light bulb does not glow when the switch is turned to the "ON" position. It might be due to the following factors:
(i) loose connections.
(ii) The connecting cables are damaged.
(iii) The cell has been used before.
(iv) The lightbulb is fused.
13. A torch needs three batteries. Draw a schematic showing how the cells are arranged within the torch so that the light bulb is lit.
13. A torch needs three batteries. Draw a schematic showing how the cells are arranged within the torch so that the light bulb is lit.
Explanation:
14. The electric cell stops producing energy when its chemical resources are depleted. Then a fresh electric cell is used in lieu of the old one. Rechargeable batteries, such as those found in cell phones, cameras, and inverters, are ones that can be used repeatedly. How?
14. The electric cell stops producing energy when its chemical resources are depleted. Then a fresh electric cell is used in lieu of the old one. Rechargeable batteries, such as those found in cell phones, cameras, and inverters, are ones that can be used repeatedly. How?
Explanation:
Rechargeable batteries can be supplied with the correct current using storage or secondary cells.
15. Paheli connected two bulbs to a cell as depicted in fig. 12.8.
where she discovered that bulb B's filament was damaged. In this circuit, will the bulb A illuminate? cite a cause.
15. Paheli connected two bulbs to a cell as depicted in fig. 12.8.
where she discovered that bulb B's filament was damaged. In this circuit, will the bulb A illuminate? cite a cause.
Explanation:
No, the bulb won't light up in this circuit since bulb B's filament is broken. Current cannot flow because of the circuit break.
16. Why are there two terminals on bulbs?
16. Why are there two terminals on bulbs?
Explanation:
The filament of a bulb is a very thin wire with two terminals that connect it to the rest of the circuit so that current can flow through it.
17. Which of the four arrangements shown in fig. 12.9—A, B, C, and D—should not be set up? Tell us why.
17. Which of the four arrangements shown in fig. 12.9—A, B, C, and D—should not be set up? Tell us why.
Explanation:
As the current in Arrangement A runs from a negative terminal to a positive terminal—exhausting the cell quickly due to the high current that would pass through it—it should not be set up.
18. A fused light bulb is dim. Why?
18. A fused light bulb is dim. Why?
Explanation:
Due to a broken filament and an incomplete circuit, a fused bulb does not glow.
19. Paheli planned to use a cell to illuminate a torch light. She was unable to obtain connecting cables, so she was given two pieces of aluminium foil instead. How well will she do? Tell us how.
19. Paheli planned to use a cell to illuminate a torch light. She was unable to obtain connecting cables, so she was given two pieces of aluminium foil instead. How well will she do? Tell us how.
Explanation:
Paheli will indeed succeed. Due to its high electrical conductivity, aluminium foil can be utilised as connecting wires for the provision of power.
20. Boojho is equipped with a cell and a solitary connecting line. Will he be able to get the wire to light without cutting it in half? With the aid of a circuit diagram, explain.
20. Boojho is equipped with a cell and a solitary connecting line. Will he be able to get the wire to light without cutting it in half? With the aid of a circuit diagram, explain.
Explanation:
Sure, following the suggested configurations, he will be able to make the bulb glow.
He can connect by going straight from the second terminal of the bulb to the positive terminal of the cell, as shown in the image. The circuit will be finished in this manner without the need for an additional connecting wire.
21. A bulb is connected to a cell in two distinct ways in Fig. 12.10 A and B.
(i) In both scenarios (Q to P or P to Q), which way will the current flow through the bulb?
(ii) In both scenarios, will the light bulb glow?
(iii) Does the direction of the current flowing through the blazing bulb affect how bright it is?
21. A bulb is connected to a cell in two distinct ways in Fig. 12.10 A and B.
(i) In both scenarios (Q to P or P to Q), which way will the current flow through the bulb?
(ii) In both scenarios, will the light bulb glow?
(iii) Does the direction of the current flowing through the blazing bulb affect how bright it is?
Explanation:
(i) The current flows from the positive terminal to the negative terminal in the case of Q to P.
The current moves from the negative terminal to the positive terminal in the instance of P to Q.
(ii) Since the circuit is complete and the current is flowing, the bulb will glow in both scenarios.
(iii) The direction of the current flowing through the lighting bulb has no bearing on how bright it is. The circuit's voltage and current levels determine how brilliant the luminous blub will be.
22. List six activities that involve the usage of electric current. Name the tools required to carry out the action as well.
22. List six activities that involve the usage of electric current. Name the tools required to carry out the action as well.
Explanation:
Activity you perform Device
Get light Torch
Make toast Toaster
Heat water Geyser
Listen to music CD player
Watch movies Laptop/TV
Cook food Microwave/Heater
23. A torch does not work, despite the fact that its contact points are in good condition. What are some potential causes of this? Please name three.
23. A torch does not work, despite the fact that its contact points are in good condition. What are some potential causes of this? Please name three.
Explanation:
The torch may not be functional for a variety of reasons, including
(i) The switch could be broken.
(ii) The cells might not be arranged correctly.
(iii) The cells might have reached capacity.
(iv) The filament in the bulb might be fused.
