NEETPhysicsMagnetic Effects of Current
Match the particles and their movement conditions in List I with the resulting magnetic force in List II. Assume all particles move with the same speed v in a uniform magnetic field of magnitude B . Let F = evB . List I List II A) Proton moving East in a B-field directed North I) Force of magnitude F towards North B) Electron moving Up in a B-field directed East II) Force of magnitude F towards South C) Alpha particl
Options
- AA - V, B - I, C - III, D - IV
- BA - I, B - II, C - III, D - IV
- CA - V, B - II, C - III, D - IV
- DA - V, B - II, C - I, D - IV
Correct answer
C. A - V, B - II, C - III, D - IV
Step-by-step solution
The magnetic Lorentz force is given by F = q( v B ) . The direction is found using the right-hand rule for the cross product, and then reversed if the charge is negative. (A) Proton ( q = +e ): Velocity is East ( i ), Magnetic field is North ( j ). F = e(v i B j ) = evB k (Up). The magnitude is F and direction is Up. Matches (V). (B) Electron ( q = -e ): Velocity is Up ( k ), Magnetic field is East ( i ). F = -e(v k B i ) = -evB j (South). The magnitude is F and direction is South. Matches (II). Forgetting the nega