Question

A charged particle of charge 4 mc enters a uniform magnetic field of induction $\overrightarrow{B}=4\overrightarrow{i}+y\overrightarrow{j}+z\overrightarrow{k}$ tesla with a velocity $\overrightarrow{V}=2\overrightarrow{i}+3\overrightarrow{j}-6\overrightarrow{k}$. If the particle continues to move undeviated, then the strength of the magnetic filed induction (B) is___ tesla.

• A. 14
• B. 2
• C. 3.5
• D. 28

Answer 1

The correct option is A 14

$\overrightarrow{B}||\overrightarrow{V}\frac{4}{2}=\frac{y}{3}=\frac{z}{-6}y=6,z=-12\overrightarrow{B}=4\hat{i}+6\hat{j}-12\hat{k},B=\sqrt{4^2+6^2+{12}^2}B=\sqrt{196}=14$