State Faraday's law of induction in words.

• A. A changing magnetic flux induces an emf equal to the magnetic flux itself.
• B. The emf in a circuit is independent of magnetic flux changes.
• C. Changing electric fields, not magnetic fields, cause emf.
• D. A changing magnetic flux through a circuit induces an emf in the circuit; ε = − dΦ/dt.

Answer: (D)