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When a ceiling fan is connected to the circuit of the solar panel, the fan does not rotate. Why?
When a magnetic compass is placed near a circuit in which an electric current is flowing, its needle deflects. Why?
An electromagnet is used in the electric bell. Give reason.
The number of primary windings and secondary windings of a transformer are not the same.
The core of a transformer is laminated. Why?
Transformers are used in mobile chargers. Give reason(s).
The frequency of a.c. in our country is 50 Hz, what does it mean?
Draw the time graph of direct current and alternating current.
Draw the magnetic field lines around the current-carrying straight wire and solenoid.
Maxwell's right-hand thumb rule shows the direction of the magnetic field produced when an electric current flows through a straight wire. Explain.
Maxwell's right-hand grip rule to find the direction of magnetic field lines of force around a solenoid. Explain.
What is the magnetic effect of current?
Define magnetic flux.
How can the magnetic field produced around straight current carrying be demonstrated by using iron dust, cardboard, and conducting straight wire? Explain it.
Draw the magnetic field developed around a straight current-
carrying wire.
What is a Solenoid? Draw a picture showing the magnetic field developed around a solenoid.
Write two uses of the solenoid.
A permanent magnet cannot be used in the electric bell, why?
Which of the following is the source of AC?
The number of secondary windings in the coil of a transformer used in a microwave oven is 12 times the number of windings in the primary coil. If it is connected to a source of 220 V, what is the secondary voltage obtained from the transformer?
What is electromagnetic induction?
State Faraday's law of electromagnetic induction.
A bulb connected to a dynamo attached to the tire of a bicycle is not found to be glowing with steady brightness. It was found that the bulb was bright, dimmed, and also turned off when the cycle came to rest. Mention the reasons for such observations based on the working principle of dynamo.
What can be done to increase the magnitude of current produced by a dynamo? Write any two ways.
Prepare a research report on any two sources of electricity in Nepal (Hydro power station, Solar power plant) including their capacity, type of electricity produced, and transmission.
What is a transformer?
Draw the block diagrams of the step-up transformer and step-down transformer and write two uses of each.
To charge a laptop of 20V, a charger with 550 primary turns is connected to an A.C. source of 220 V. Calculate the number of secondary windings of the charger.
The number of secondary windings in the coil of a transformer used in a microwave oven is 10 times the number of windings in the primary coil. If it is connected to a source of 220 V, what is the secondary voltage obtained from the transformer?
The ratio of the number of the primary winding to the number of secondary windings of a transformer is 22:1. If an adopter with that transformer is connected to an electric circuit having a potential difference of 220 V, calculate the output voltage so obtained.
What is the frequency of DC? Why?
An electric material production company saw the demand of transformer in the market.
- If the company manufactures transformers with number of primary coil 200 turns and secondary coil 100 turns. What type of transformer is formed?
- If 50V DC is passed in the primary coil in the transformer manufactured by the company, what will be the secondary voltage?
- What is the relation between input and output energy in the transformers?
- What is the use of transformer given in no. '1', in our daily life?
A 12 V rickshaw is charged at a charge station in. Dhangadhi. It is charged using a transformer having 550 turns in primary coil connected in 220 V AC, line.
- Calculate the number of turns in secondary coil of transformer.
- Mention the type of transformer used to charge rickshaw. Write down one difference between this transformer and the transformer used in power house.
Which physical quantity always remains the same in a transformer?
If number of turns of wire in primary coil of a transformer shown in the diagram is 4 times more than that in secondary coil. What will be the value of secondary voltage?
Electricity supply in your house is of 220 V. You have two transformers one with more number of turns in primary coil than in secondary coil and another with less number of turns in primary coil than in secondary coil. Which transformer will you select to play a radio set that needs 12 V?
In what two ways electric generator differs from electric motor?
What is the major similarity in electric motor and current generator?
When 220 V is passed in the primary coil of a transformer, 440 V is induced in secondary coil. If the number of turns in secondary coil is 350:
- What will be the number of turns in primary coil?
- What will happen if core of a transformer is not laminated?
- Can it be used by connecting with battery?
What amount of current can flow in the kettle written with 750 watt and 220 V?
Which one is the way to increase the magnitude of induced emf in a generator?
What will you do to increase the magnetic flux for the coil without changing the magnetic field of the bar magnet?
Write the unit of current electricity and pressure.
A model of DC motor as shown in the diagram was made by Rakesh. He removed the enamels of the ends of the coil and used new cell. When he brought a magnet close to the coil it did not move although there was no problem in circuit? What might be the possible causes of it? Mention any two of them.
Which scientist discovered the magnetic effect of electric current?
When a ceiling fan is connected to the circuit of the solar panel, the fan does not rotate. Why?
When a magnetic compass is placed near a circuit in which an electric current is flowing, its needle deflects. Why?
An electromagnet is used in the electric bell. Give reason.
The number of primary windings and secondary windings of a transformer are not the same.
The core of a transformer is laminated. Why?
Transformers are used in mobile chargers. Give reason(s).
The frequency of a.c. in our country is 50 Hz, what does it mean?
Draw the time graph of direct current and alternating current.
Draw the magnetic field lines around the current-carrying straight wire and solenoid.
Maxwell's right-hand thumb rule shows the direction of the magnetic field produced when an electric current flows through a straight wire. Explain.
Maxwell's right-hand grip rule to find the direction of magnetic field lines of force around a solenoid. Explain.
What is the magnetic effect of current?
Define magnetic flux.
How can the magnetic field produced around straight current carrying be demonstrated by using iron dust, cardboard, and conducting straight wire? Explain it.
Draw the magnetic field developed around a straight current-
carrying wire.
What is a Solenoid? Draw a picture showing the magnetic field developed around a solenoid.
Write two uses of the solenoid.
A permanent magnet cannot be used in the electric bell, why?
Which of the following is the source of AC?
The number of secondary windings in the coil of a transformer used in a microwave oven is 12 times the number of windings in the primary coil. If it is connected to a source of 220 V, what is the secondary voltage obtained from the transformer?
What is electromagnetic induction?
State Faraday's law of electromagnetic induction.
A bulb connected to a dynamo attached to the tire of a bicycle is not found to be glowing with steady brightness. It was found that the bulb was bright, dimmed, and also turned off when the cycle came to rest. Mention the reasons for such observations based on the working principle of dynamo.
What can be done to increase the magnitude of current produced by a dynamo? Write any two ways.
Prepare a research report on any two sources of electricity in Nepal (Hydro power station, Solar power plant) including their capacity, type of electricity produced, and transmission.
What is a transformer?
Draw the block diagrams of the step-up transformer and step-down transformer and write two uses of each.
To charge a laptop of 20V, a charger with 550 primary turns is connected to an A.C. source of 220 V. Calculate the number of secondary windings of the charger.
The number of secondary windings in the coil of a transformer used in a microwave oven is 10 times the number of windings in the primary coil. If it is connected to a source of 220 V, what is the secondary voltage obtained from the transformer?
The ratio of the number of the primary winding to the number of secondary windings of a transformer is 22:1. If an adopter with that transformer is connected to an electric circuit having a potential difference of 220 V, calculate the output voltage so obtained.
What is the frequency of DC? Why?
An electric material production company saw the demand of transformer in the market.
- If the company manufactures transformers with number of primary coil 200 turns and secondary coil 100 turns. What type of transformer is formed?
- If 50V DC is passed in the primary coil in the transformer manufactured by the company, what will be the secondary voltage?
- What is the relation between input and output energy in the transformers?
- What is the use of transformer given in no. '1', in our daily life?
A 12 V rickshaw is charged at a charge station in. Dhangadhi. It is charged using a transformer having 550 turns in primary coil connected in 220 V AC, line.
- Calculate the number of turns in secondary coil of transformer.
- Mention the type of transformer used to charge rickshaw. Write down one difference between this transformer and the transformer used in power house.
Which physical quantity always remains the same in a transformer?
If number of turns of wire in primary coil of a transformer shown in the diagram is 4 times more than that in secondary coil. What will be the value of secondary voltage?
Electricity supply in your house is of 220 V. You have two transformers one with more number of turns in primary coil than in secondary coil and another with less number of turns in primary coil than in secondary coil. Which transformer will you select to play a radio set that needs 12 V?
In what two ways electric generator differs from electric motor?
What is the major similarity in electric motor and current generator?
When 220 V is passed in the primary coil of a transformer, 440 V is induced in secondary coil. If the number of turns in secondary coil is 350:
- What will be the number of turns in primary coil?
- What will happen if core of a transformer is not laminated?
- Can it be used by connecting with battery?
What amount of current can flow in the kettle written with 750 watt and 220 V?
Which one is the way to increase the magnitude of induced emf in a generator?
What will you do to increase the magnetic flux for the coil without changing the magnetic field of the bar magnet?
Write the unit of current electricity and pressure.
A model of DC motor as shown in the diagram was made by Rakesh. He removed the enamels of the ends of the coil and used new cell. When he brought a magnet close to the coil it did not move although there was no problem in circuit? What might be the possible causes of it? Mention any two of them.
Which scientist discovered the magnetic effect of electric current?