Q. In a parabola spectrograph, the velocities of four positive ions $P,Q,R$ and $S$ are $v_{1},v_{2},v_{3}$ and $v_{4}$ respectively. Then
A) $v_{1} > v_{2} > v_{3} > v_{4}$
B) $v_{1} < v_{2} < v_{3} < v_{4}$
C) $v_{1} = v_{2} = v_{3} = v_{4}$
D) $v_{1} < < v_{2} > v_{3} < v_{4}$
Explanation
(a) $\because x \propto \frac{1}{v^{2}}.$ The ion whose deflection is less, its velocity will be more. From the curve $x_{1} < x_{2} < x_{3} < x_{4},$ therefore $v_{1} > v_{2} > v_{3} > v_{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.