Question

An electron and a proton move in a uniform magnetic field with same speed $20m/s$ perpendicular to the magnetic field ($1T$). What are the forces they will experience ?

• A. $0N,0N$
• B. $32\times {10}^{-19}N,32\times {10}^{-19}N$
• C. $-32\times {10}^{-19}N,32\times {10}^{-19}N$
• D. $-32\times {10}^{-18}N,32\times {10}^{-18}N$

Answer 1

Answer: (C)

$-32\times {10}^{-19}N,32\times {10}^{-19}N$

The force acting on the charged particle placed in magnetic field is given by,
$F=qVB\sin \theta =\pm 1.6\times {10}^{-19}\times 20\times 1=\pm 32\times {10}^{-19}N$