Advertisements
Advertisements
प्रश्न
The following diagram shows a spiral coil wound on a hollow carboard tube AB. A magnetic compass is placed close to it. Current is switched on by closing the key.
- What will be the polarity at the ends A and B?
- How will the compass needle be affected? Give reason.
Advertisements
उत्तर
- A - North pole, B - South pole.
- The north end of the compass is repelled and moves away because a north pole is generated at end A, where current flows anticlockwise and enters the negative pole of the battery.
APPEARS IN
संबंधित प्रश्न
How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.
The figure shows a solenoid wound on a core of soft iron. Will the end A be a N pole or S pole when the current flows in the direction shown?
How is the magnetic field due to a solenoid carrying current affected if a soft iron bar is introduced inside the solenoid?
The diagram shows a current-carrying coil passing through a cardboard sheet. Draw three magnetic lines of force on the board.
State two factors on which magnitude of magnetic field at the centre depends.
Sketch the lines of force of the magnetic field of a solenoid. How does its field compare with that of a bar magnet?
The magnetic field lines outside a bar magnet:
The factors on which one magnetic field strength is produced by current-carrying solenoids depends are
The diagram below shows a magnet moved near a coil along its axis. Which of the diagram shows correct flow of current during this motion?
The diagram below shows an insulated copper wire wound around a hollow cardboard cylindrical tube. Answer the questions that follow:
- What are the magnetic poles at A and B when the key K is closed?
- State two ways to increase the strength of the magnetic field in this coil without changing the coil.
- If we place a soft iron bar at the centre of the hollow cardboard and replace the DC source with an AC source then will it attract small iron pins toward itself when the current is flowing through the coil?
A circuit contains a battery, a variable resistor and a solenoid. The figure below shows the magnetic field pattern produced by the current in the solenoid.
- State how the magnetic field pattern indicates regions where the magnetic field is stronger.
- What happens to the magnetic field when the current in the circuit is reversed?
