Two protons P and Q moving with the same speed enter magnetic field `B_(1)andB_(2)` respectively at right angles to the field directions. If `B_(2)` is greater than `B_(1)` for which of the protons P and Q the circular path in the magnetic field will have a smaller radius?

Explanation

(a) Electron if it moves parallel or anti-parallel to the magnetic field.
(b) `r = (mv)/(Bq) `
Therefore , `r_(1)/r_(2) = B_(2)/B_(1)`
As `|vec B_(2)| gt |vec B_(1)|" therefore , " r_(2) lt r_(1)`