JEE Main20202 Sep 2020Morning ShiftPhysicsMagnetic Effects of CurrentActual
A beam of protons with speed 4 × 10 5 m s - 1 enters a uniform magnetic field of 0 . 3 T at an angle 60 ° to the magnetic field, the pitch of the resulting helical path of protons is close to : (Mass of the proton = 1 . 67 × 10 - 27 kg , charge of the proton = 1 . 69 × 10 - 19 C )
Options
- A2   cm
- B5 cm
- C12   cm
- D4   cm
Correct answer
D. 4   cm
Step-by-step solution
Pitch = ( Vcos θ ) T = ( Vcos θ ) 2 π m eB = 4 × 10 5 cos 60 ° 2 π 0 . 3 × 10 1 . 67 × 10 - 27 1 . 69 × 10 19 4   cm