Question

A charge particle is moving in a uniform field $(2\hat i+3\hat j)T$. If it has an acceleration of $(α\hat i−4\hat j)\ m/s^2$, then the value of α will be

• A. 3
• B. 6
• C. 12
• D. 2

Answer 1

Answer: (B)

6

Answer 2

As magnetic force is perpendicular to magnetic field.
So, $\vec F⋅\vec B$ must be $0$.
So, $2α–12=0$
$2α=12$
$α=\frac {12}{2}$
$α=6$

So, the correct option is (B): $6$.