Direction Sense

Step 1: Recall Lenz's Law.

Lenz's Law is a fundamental principle in electromagnetism that describes the direction of an induced current. It states that:

The induced current in a conductor will flow in such a direction as to oppose the change that produced it.

This law helps determine the direction of the induced current when a magnetic field changes or a conductor moves through a magnetic field.

Step 2: Analyze the options.

• (1) Direction of the magnetic field line at any point: This is determined by the right-hand rule for magnetic fields, not Lenz's Law.
• (2) Magnetic force acting on a current-carrying wire in a magnetic field: The magnetic force on a current-carrying wire is given by the formula , where is the current, is the length of the wire, is the magnetic field strength, and is the angle between the wire and the magnetic field. This is described by the Lorentz force law, not Lenz's Law.
• (3) Direction of induced current: Lenz's Law specifically determines the direction of the induced current in response to a changing magnetic field or motion through a magnetic field. This is the correct application of Lenz's Law.
• (4) Pole strength of the bar magnet: The pole strength of a bar magnet is related to its magnetic moment and is not directly determined by Lenz's Law.

Final Answer: Lenz's Law gives the , which corresponds to option .

Step 1: Recall Lenz's Law.

Lenz's Law is a fundamental principle in electromagnetism that describes the direction of an induced current. It states that:

The induced current in a conductor will flow in such a direction as to oppose the change that produced it.

This law helps determine the direction of the induced current when a magnetic field changes or a conductor moves through a magnetic field.

Step 2: Analyze the options.

• (1) Direction of the magnetic field line at any point: This is determined by the right-hand rule for magnetic fields, not Lenz's Law.
• (2) Magnetic force acting on a current-carrying wire in a magnetic field: The magnetic force on a current-carrying wire is given by the formula , where is the current, is the length of the wire, is the magnetic field strength, and is the angle between the wire and the magnetic field. This is described by the Lorentz force law, not Lenz's Law.
• (3) Direction of induced current: Lenz's Law specifically determines the direction of the induced current in response to a changing magnetic field or motion through a magnetic field. This is the correct application of Lenz's Law.
• (4) Pole strength of the bar magnet: The pole strength of a bar magnet is related to its magnetic moment and is not directly determined by Lenz's Law.

Final Answer: Lenz's Law gives the , which corresponds to option .