Lenz’s law of electromagnetic induction states that

Step 1: Analyze the question The question asks for the correct statement of Lenz's law, not Faraday's law or any other law of electromagnetism.

Step 2: The concept Lenz's law deals with the direction of an induced current or emf. It says the induced current flows in a direction that opposes the change in magnetic flux that produced it. This follows from conservation of energy. If the induced current aided the change, energy would be created from nothing.

Example: if you push the north pole of a magnet toward a coil, the coil's induced current creates a north pole facing the magnet. This repels the magnet and opposes its motion. That is why the formula for Faraday's law carries a negative sign:

ε = −N (dΦ/dt)

The negative sign represents Lenz's law.

Step 3: Check each option

• A. A force on a current-carrying conductor in a magnetic field. This is the motor effect, which is described by Fleming's left-hand rule. ✗
• B. The induced current is in a direction that opposes the change producing it. This is exactly Lenz's law. ✓
• C. The induced emf is proportional to the rate of change of flux linkage. This is Faraday's second law (the magnitude). ✗
• D. The induced emf is proportional to the current producing the flux. This is not a standard law. It is loosely related to mutual inductance. ✗
• E. An emf is induced whenever the flux linked with a circuit changes. This is Faraday's first law. ✗

Step 4: Answer The correct option is B.

Tip: Remember the pairing:

• Faraday tells you how much emf is induced (magnitude).
• Lenz tells you which way it acts (direction, "opposes the change").

Whenever you see the words "oppose" or "direction" with induction, think Lenz.