Identify the correct statements among the following:(A) The magnetic…

The correct answer is Option (3) → (A), (B) and (D) only

The magnetic flux through a coil is \( \Phi = BA\cos\theta \), where \( \theta \) is the angle between the field and the normal to the plane of the coil. An emf is induced only when this flux changes.

(A) The magnetic flux through a coil is maximum when its plane is perpendicular to the direction of the magnetic field. — Correct. The normal is then along the field, \( \theta = 0 \) and \( \Phi = BA \), the largest possible value.

(B) No emf is induced when a coil and a magnet move with the same velocity in the same direction. — Correct. There is no relative motion, so the flux through the coil does not change.

(C) An emf is induced when a closed loop moves totally inside a uniform magnetic field. — Incorrect. While the whole loop stays inside a uniform field, the same flux passes through it at every position, so no emf is induced.

(D) The magnetic flux through a coil can be changed by rotating the coil in the magnetic field. — Correct. Rotation changes \( \theta \) and hence \( BA\cos\theta \); this is how an ac generator works.

NCERT (2026-27):
The Experiments of Faraday and Henry – “… It shows that it is the relative motion between the magnet and the coil that is responsible for generation (induction) of electric current in the coil.”

Magnetic Flux – “… Magnetic flux through a plane of area A placed in a uniform magnetic field B (Fig. 6.4) can be written as

    \( \displaystyle \Phi_B = \mathbf{B} \cdot \mathbf{A} = BA\cos\theta \qquad (6.1) \)

where θ is angle between B and A.”