Question

The figure shows a conducting ring of radius $R$. A uniform steady magnetic field $B$ lies perpendicular to the plane of the ring in a circular region of radius $r(<R)$. If the resistance per unit length of the ring is $\lambda$, then the current induced in the ring when its radius gets doubled is

• A. $\frac{BR}{\lambda }$
• B. $\frac{2BR}{\lambda }$
• C. $\text{Zero}$
• D. $\frac{B{r}^2}{4R\lambda }$

Answer 1

The correct option is C $\text{Zero}$

Even if radius is doubled, flux is not going to change.
$\therefore$ Current induced in the ring zero.