A proton enters a magnetic field with a velocity of 2.5 x 10⁷ m/s making angle 30° with the magnetic field. What is the force on the proton ? (Given B = 2.5T)

• A

  $1\cdot 25\times {10}^{-12}\mathrm{N}$

• B

  $2\cdot 5\times {10}^{-12}\mathrm{N}$

• C

  $5\cdot 0\times {10}^{-12}\mathrm{N}$

• D

  $7\cdot 5\times {10}^{-12}\mathrm{N}$