Q 12-06-043JEE MainJEE Main 2025 (28 Jan, Shift 2)Medium
A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field $B$ exists into the page. The bar starts to move from the vertex at time $t = 0$ with a constant velocity. If the induced EMF is $E \propto t^n$, then the value of $n$ is ______.
Numerical value type. Enter your answer.
Answer: 1
The rails form a V. After time $t$ the bar is at distance $vt$ from the vertex, and the length of bar between the rails is proportional to that distance: $l \propto vt$.
$$E = Blv \propto t$$
$n = 1$
Solution by Sreeraj P, M.Sc Physics