A coil of area A and N turns is rotating with angular velocity ω in a uniform magnetic field \(\rm \vec B\) about an axis perpendicular to \(\rm \vec B\). Magnetic flux φ and induced emf ε across it, at an instant when \(\rm \vec B\) is parallel to the plane of coil, are :
1
φ = AB, ε = 0
2
φ = 0, ε = NABω
3
φ = 0, ε = 0
4
φ = AB, ε = NABω