An electron and a proton enter a magnetic field perpendicularly. Both have same kinetic energy. Which of the following is true 

(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

(b) We have qvB=mv2r or r=mvqB=2mKqB
For same kinetic energy K, we have rm
Hence path of proton will have larger r and is therefore less curved.

Difficulty Level:

  • 22%
  • 43%
  • 31%
  • 6%