Question

A positively charged particle of $1.0C$ is moving upward at a velocity of $2.0\times {10}^{3}m/s$ in a magnetic field of strength $4.0\times {10}^{-4}T$, directed into the page. Calculate the magnetic force experienced by the charge particle.

• A. $0.8N$ to the left
• B. $0.8N$ to the right
• C. $2.0\times {10}^{-7}N$ to the left
• D. $2.0\times {10}^{-7}N$ to the right
• E. $5.0\times {10}^{6}N$ to the left

Answer 1

The correct option is A $0.8N$ to the left

Given : $B=4.0\times {10}^{-4}T$ $Q=1.0C$ $v=2.0\times {10}^3$ $m/s$

Magnetic force $\overrightarrow{F}=Q(\overrightarrow{v}\times \overrightarrow{B})$

Thus from figure, $(\overrightarrow{v}\times \overrightarrow{B})$ points in the left direction, thus force acts to the left.

Force on the particle $|F|=QvB=1\times 2\times {10}^3\times 4\times {10}^{-4}=0.8N$ (to the left)