(c) $\ \ \ \ \ \ \ \ r = \frac{mv}{Bq}$ $\Rightarrow \ \ r = \frac{v}{B\frac{q}{m}} = \frac{2 \times 10^{5}}{0.05 \times 2.5 \times 10^{7}}$ $\ \ \ \ \ \ \ \ \ \ = \frac{2 \times 10^{7}}{12.5 \times 10^{7}} = \frac{200}{12.5}\ cm = 16\ cm$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.