Question

Total emf induced in a coil with \( N \) turns and changing magnetic flux \( \frac{d\phi_B}{dt} \) is:

• A. \( -N \frac{d\phi_B}{dt} \)
• B. \( N \frac{d\phi_B}{dt} \)
• C. \( -N \frac{d^2\phi_B}{dt^2} \)
• D. \( -\frac{d\phi_B}{dt} \)

Hint:

Always apply the negative sign for Lenz’s law in Faraday’s equation.

Answer 1

The Correct Option is A

By Faraday’s law: \( \text{emf} = -N \frac{d\phi_B}{dt} \)
Where \( N \) is the number of turns and \( \phi_B \) is the magnetic flux.