Lenz's Law Opposes Magnet Motion

Steps:

• Bar magnet falls north pole first through vertical solenoid, increasing flux downward at the top end Y.
• Lenz's law induces current to create opposing flux, making end Y a north pole to repel the approaching north pole.
• This repulsion slows the magnet's fall, conserving energy.
• Solenoid acts as electromagnet with north at Y, resulting in north-north repulsion.

Why A is correct:

• Lenz's law dictates induced polarity opposes flux change, creating repulsion to hinder motion (Faraday's law of induction).

Why the others are wrong:

• B: South pole at Y would attract the north pole, aiding motion against Lenz's law.
• C: South attraction accelerates the magnet, violating opposition to flux increase.
• D: North attraction implies no opposition, contradicting induced emf direction.

Final answer: A