JEE Main · 2025 · 28 Jan 2025 · Shift 2 · Electromagnetic Induction

The two rails meet at a vertex with a total opening angle of $60^{\circ }$ ($30^{\circ }$ on each side of the axis along which the bar slides). At time $t$, the bar has moved a distance $x=vt$ from the vertex, and the length of the bar in contact with the rails at that instant is


The motional EMF of a rod of length $\ell$ moving with speed $v$ in a field $B$ perpendicular to the plane is


Substituting $\ell =\frac{2x}{\sqrt{3}}$ with $x=vt$:


So $E\propto t^1$, giving $n=1$.