The amplitude of velocity of a particle acted on by a force F=cos $\omega$ t along the x direction, is given by $x=\frac{1}{\sqrt{\left[a{\omega }^2-b\omega +c\right]}}$ where a,b,c, are constants and $b^2<4\text{ ac. }$. For what value of $\omega$ does the resonance occur?

• A

  $\omega =\frac{\mathrm{b}}{2\mathrm{a}}$

• B

  $\omega =\frac{\mathrm{b}}{\mathrm{a}}$

• C

  $\omega =\mathrm{c}$

• D

  $\omega =0$