Question

A particle of mass 0.5 gm and charge $2.5\times {10}^{-8}C$ is moving with velocity $6\times {10}^{4}m/s$. What should be the minimum value of magnetic field acting on it, so that the particle is able to move in a straight line ? $(g=9.8m/se{c}^2)$

• A. $0.327Weber/m^2$
• B. $3.27Weber/m^2$
• C. $32.7Weber/m^2$
• D. none of these

Answer 1

The correct option is A $0.327Weber/m^2$

We know force= mass$\times$acceleration due to gravity=0.5$\times$ 9.8 m/$s^2$.

Thus force=4.9 N

Also we know Force$F=q[v\times B]$

$B=\frac{4.9}{2.5\times 6\times {10}^4}=0.327$