Advertisements
Advertisements
प्रश्न
Refer to the image below and state how the magnetic field pattern indicates regions where the magnetic field is stronger outside the magnet. What happens to the magnetic field when the current in the circuit is reversed?
Advertisements
उत्तर १
The magnetic field strength is more in the region where the field lines are crowded. This means the field strength is maximum near the poles and it reduces as we go away from the poles. The direction of the magnetic field is also reversed.
उत्तर २
The diagram shows a solenoid (a coil of wire) connected to a battery and a switch. The lines drawn around the solenoid represent magnetic field lines generated when current flows through the solenoid.
Identifying Stronger Magnetic Field Regions Outside the Magnet
-
The density of magnetic field lines indicates the strength of the magnetic field.
-
Where the lines are closer together, the magnetic field is stronger.
-
Outside the solenoid, the field lines are more spread out, meaning the magnetic field is weaker there.
-
Therefore, inside the solenoid, where the lines are very close and mostly parallel, the field is stronger.
-
Outside, the field is weaker, but you can still identify slightly stronger regions just around the ends of the solenoid where the lines begin to spread — these regions are closer to the poles.
Effect of Reversing the Current
-
The polarity of the magnetic field also reverses.
-
This means the north and south poles of the solenoid switch places.
-
As a result, the direction of the magnetic field lines changes — they will now emerge from the other end of the solenoid and return into the opposite end.
-
However, the pattern of the magnetic field lines (shape and spread) remains the same.
APPEARS IN
संबंधित प्रश्न
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?
The adjacent diagram shows a small magnet placed near a solenoid AB. Current is switched on in the solenoid by pressing the key K.
- State the polarity at the ends A and B.
- Will the magnet be attracted or repelled? Give a reason for your answer.
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.
State two ways by which the magnetic field due to a current carrying solenoid can be made stronger.
Why does a current carrying freely suspended solenoid rest along a particular direction? State the direction in which it rests.
What is a solenoid? Why do we usually keep its diameter small in comparison to its length?
Which of the following diagrams correctly shows the magnetic field produced by a current-carrying wire?
For a current in a long straight solenoid, N-pole and S-pole are created at the two ends. Among the following statements, the incorrect statement is ____________.
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?
For the current carrying solenoid as shown, draw magnetic field lines and give reason to explain that out of the three points A, B and C, at which point the field strength is maximum and at which point it is minimum?
