Question

A proton is moving in a field of induction $[2\overrightarrow{i}+4\overrightarrow{j}]T$ with velocity $[3\times {10}^7\overrightarrow{i}]m{s}^{-1}$. The force experienced by it will be?

• A. $16.8\times {10}^{-12}(+\hat{k})N$
• B. $6\times {10}^{-7}(-\hat{k})N$
• C. $12\times {10}^{-7}(+\hat{k})N$
• D. $0$

Answer 1

The correct option is A $16.8\times {10}^{-12}(+\hat{k})N$

$\overrightarrow{F}=q(\overrightarrow{V}\times \overrightarrow{B})=1.6\times {10}^{-19}[3\times {10}^7\hat{i}]\times [2\hat{i}+4\hat{j}]=1.6\times {10}^{-19}\times 3\times {10}^7\times 4\hat{k}\overrightarrow{F}=16.8\times {10}^{-12}\hat{k}$