Given that, area, A=10m2 Magnetic field, B=0.3NA−1m−1 T=8s When plane is perpendicular to field, then flux passing through it, φ=BA‌cos‌0∘=0.3×10×1=3Wb When plane is parallel to field, then flux passing through it, φ=BA‌cos‌90∘=0 For 0∘ to 90∘ position, average emf, εavg=‌
∆φ
∆t
=‌
φ90∘−φ0∘
T
4
=‌
3−0
2
=‌
3
2
V For 90∘ to 180∘ position, savg=−‌
φ180∘−φ90∘
T
4
=−‌
0−3
2
=‌
3
2
V Negative sign has been taken because flux associated to plane is decreasing. Similarly, for 180∘ to 270∘ position, εavg=−‌
φ270∘−φ180∘
T
4
=−‌
3−0
2
=‌
−3
2
V For 270∘ to 360∘ position, ε‌avg ‌=+‌