As we know that, Magnetic flux, ϕ=B.A=BA‌cos‌θ ...(i) where, B is magnetic field and A is area of cross-section. But dot product makes flux a scalar quantity Now, from Eq. (i), we get Ifθ=0°‌‌‌‌ϕ=BA‌Wb θ=90°‌‌‌‌ϕ=0‌Wb θ=180°‌‌‌‌ϕ=−BA‌Wb Hence, Assertion is false and Reason is true.