Consider the following figure.
Taking the length along vertical direction,
lsin30°= The expression of variation of magnetic field along z-axis is,
B=B0()3 The expression for induced emf is,
E=Blv Now, consider a small element of length
dy at a distance
y from origin along Y-axis, then emf of element
dE=B(dy)v0 =B0v0dy The emf of the rod comes out to be,
E=y3dy =[ ]0L∕2 =