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QJEEM19Ph4748: JEE Main 2019 Physics - Class 12 JEEM19Ph4748 Solution: A proton and an -particle (with their masses in the ratio of 1…

A proton and an α\alpha -particle (with their masses in the ratio of 1 : 4 and charges in the ratio of 1 : 2) are accelerated from rest through a potential difference V. If a uniform magnetic field (B) is set up perpendicular to their velocities, the ratio of the radii rp : r α\alpha of the circular paths described by them will be ;

Multiple Choice Options

  • A 1:31:\sqrt 3
  • B 1:03
  • C 1:21:\sqrt 2
  • D 1:02

Step-by-Step Verified Solution

KE = q Δ\Delta V

r = 2mqΔVqB{{\sqrt {2mq\Delta V} } \over {qB}}

r ∝\propto mq\sqrt {{m \over q}}

rpr∝{{{r_p}} \over {{r_ \propto }}} = 12{1 \over {\sqrt 2 }}

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