JEE MAIN - Physics (2012 - No. 12)
Proton, deuteron and alpha particle of same kinetic energy are moving in circular trajectories in a constant magnetic field. The radii of proton, denuteron and alpha particle are respectively $${r_p},{r_d}$$ and $${r_\alpha }$$. Which one of the following relation is correct?
$${r_\alpha } = {r_p} = {r_d}$$
$${r_\alpha } = {r_p} < {r_d}$$
$${r_\alpha } > {r_d} > {r_p}$$
$${r_\alpha } = {r_d} > {r_p}$$
설명
$$r = {{\sqrt {2mv} } \over {qB}} \Rightarrow r \times v{{\sqrt m } \over q}$$
Thus we have, $${r_\alpha } = {r_p} < {r_d}$$
Thus we have, $${r_\alpha } = {r_p} < {r_d}$$