Easy MCQ +4 / -1 PYQ · JEE Mains 2022

Two charged particles, having same kinetic energy, are allowed to pass through a uniform magnetic field perpendicular to the direction of motion. If the ratio of radii of their circular paths is $6: 5$ and their respective masses ratio is $9: 4$. Then, the ratio of their charges will be :

  1. A 8 : 5
  2. B 5 : 4 Correct answer
  3. C 5 : 3
  4. D 8 : 7

Solution

<p>We know that $R = {{mv} \over {Bq}} = \sqrt {{{2mK} \over {Bq}}}$</p> <p>$\Rightarrow$ Ratio of radii $$ = {{{R_1}} \over {{R_2}}} = \sqrt {{{{m_1}} \over {{m_2}}}} {{{q_2}} \over {{q_1}}}$$</p> <p>$\Rightarrow {6 \over 5} = \sqrt {{9 \over 4}} {{{q_2}} \over {{q_1}}}$</p> <p>$$ \Rightarrow {{{q_1}} \over {{q_2}}} = {3 \over 2} \times {5 \over 6} = {5 \over 4}$$</p>

About this question

Subject: Physics · Chapter: Magnetic Effects of Current · Topic: Biot-Savart Law

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