Magnetic Effects Of Current Question 301
Question: An electron and a proton enter a magnetic field perpendicularly. Both have same kinetic energy. Which of the following is true [MP PET 1999]
Options:
A) Trajectory of electron is less curved
B) Trajectory of proton is less curved
C) Both trajectories are equally curved
D) Both move on straight-line path
Show Answer
Answer:
Correct Answer: B
Solution:
We have $ qvB=\frac{mv^{2}}{r} $ or $ r=\frac{mv}{qB}=\frac{\sqrt{2mK}}{qB} $ For same kinetic energy K, we have $ r\propto \sqrt{m} $ Hence path of proton will have larger r and is therefore less curved.
BETA
