Lenz’s law of electromagnetic induction states that

Step 1: Analyze the question The question asks for the statement of Lenz's law. Each option describes a different idea in electromagnetism, so the task is to match each statement to the correct law.

Step 2: Explain the concept Lenz's law is about the direction of an induced current. 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. The negative sign in Faraday's law, e = -N(dΦ/dt), expresses this opposition.

Step 3: Check each option

• A. An e.m.f. is induced whenever the flux linked with a circuit changes. This is Faraday's first law, not Lenz's law.
• B. The induced e.m.f. is proportional to the rate of change of flux linkage. This is Faraday's second law.
• C. The induced current flows in a direction that opposes the change producing it. This is Lenz's law.
• D. A force acts on a current-carrying conductor in a magnetic field. This is the motor effect, described by Fleming's left-hand rule.
• E. The induced e.m.f. is proportional to the current producing the flux. This loosely describes mutual inductance and is not Lenz's law.

Step 4: Answer

Tip: Remember the pairing "Faraday = how much (magnitude), Lenz = which way (direction)". Whenever you see the word "oppose" in a question about induction, think Lenz. Fleming's right-hand rule (generator) gives the direction of induced current, and it is consistent with Lenz's law.