Advertisements
Advertisements
प्रश्न
- What name is given to a cylindrical coil of diameter less than its length?
- If a piece of soft iron is placed inside the coil mentioned in part (a) and current is passed in the coil from a battery, what name is then given to the device so obtained?
- Give one use of the device mentioned in part (b).
Advertisements
उत्तर
- Solenoid is a cylindrical coil of diameter less than its length.
- The device so obtained is electromagnet.
- It is used in electric bell.
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?
Draw a diagram to represent the magnetic field lines along the axis of a current carrying solenoid. Mark arrows to show the direction of current in the solenoid and the direction of magnetic field lines.
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.
A current carrying solenoid when freely suspended, it always rests in ______ direction.
The magnetic field lines outside a bar magnet:
What does the divergence of magnetic field lines near the ends of a current carrying straight solenoid indicate?
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?
When does a solenoid behave as a magnet? Draw the pattern of the magnetic field produced inside it showing the directions of the magnetic field lines.
