Question

Why can't two magnetic field lines cross each other? Draw magnetic field lines showing the direction of the magnetic field due to a current-carrying long straight solenoid. State the conclusion which can be drawn from the pattern of magnetic field lines inside the solenoid. Name any two factors on which the magnitude of the magnetic field due to this solenoid depends.

Hint:

The magnetic field inside a solenoid is uniform and strong, resembling the field of a bar magnet. The strength of the field depends on the current and the number of turns per unit length of the solenoid.

Answer 1

Two factors affecting the magnitude of the magnetic field due to a current-carrying coil:
1. Current (I): The magnetic field strength is directly proportional to the current flowing through the coil. An increase in current results in a stronger magnetic field.
2. Number of turns (N): The magnetic field strength is directly proportional to the number of turns in the coil. More turns result in a stronger magnetic field. Two magnetic field lines cannot cross each other because if they did, it would mean that the magnetic field has two different directions at the same point, which is not possible. The magnetic field at any given point has a definite direction, and the field lines represent the path of the magnetic field in space. Magnetic Field Due to a Current-Carrying Solenoid:
A solenoid is a long coil of wire that produces a uniform magnetic field inside. When a current flows through the solenoid, it generates a magnetic field with the following properties:
- The magnetic field inside the solenoid is strong and uniform.
- The field lines are parallel to each other and point in the same direction inside the solenoid.
- Outside the solenoid, the magnetic field lines form closed loops and resemble the field lines of a bar magnet.
Magnetic field lines inside the solenoid are straight and parallel, indicating a uniform magnetic field. The direction of the magnetic field can be determined using the right-hand rule for solenoids:
- If you curl the fingers of your right hand in the direction of current flow in the solenoid, your thumb will point in the direction of the magnetic field inside the solenoid.
Conclusion:
From the pattern of magnetic field lines inside the solenoid, we can conclude that the solenoid creates a uniform magnetic field inside, similar to that of a bar magnet. The magnetic field outside the solenoid behaves like the field of a simple magnet, with field lines emerging from one end and curving around to the other. Two Factors Affecting the Magnitude of the Magnetic Field in a Solenoid:
1. Current (I): The magnetic field strength is directly proportional to the current passing through the solenoid.
2. Number of turns per unit length (n): The magnetic field strength increases with the number of turns per unit length. More turns result in a stronger magnetic field.