Two ions having same mass have charges in the ratio 1 : 2. They are projected normally in a uniform magnetic field with their speeds in the ratio 2 : 3. The ratio of the radii of their circular trajectories is :
Solution
$$R = {{mv} \over {qB}} \Rightarrow {{{R_1}} \over {{R_2}}} = {{{{m{v_1}} \over {{q_1}B}}} \over {{{m{v_2}} \over {{q_2}B}}}} = {{{v_1}} \over {{q_1}}} \times {{{q_2}} \over {{v_2}}} = {{{q_2}} \over {{q_1}}} \times {{{v_1}} \over {{v_2}}}$$<br><br>$= {2 \over 1} \times \left( {{2 \over 3}} \right) = {4 \over 3}$
About this question
Subject: Physics · Chapter: Magnetic Effects of Current · Topic: Biot-Savart Law
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