Two very small balls, each having mass m, are attached to two massless rods of length l. Now these rods are joined to form V like figure having angle 60°. This assembly is now hinged in a vertical plane so that it can rotate without any friction about a horizontal axis (perpendicular to the plane of figure) as shown in the figure. The period of small oscillation of this assembly is

• A

  2$\mathrm{\pi }\sqrt{\frac{2\mathrm{l}}{\mathrm{g}}}$

• B

  $2\mathrm{\pi }\sqrt{\frac{2\mathrm{l}}{\sqrt{3}\mathrm{g}}}$

• C

  $2\mathrm{\pi }\sqrt{\frac{\mathrm{l}}{\sqrt{3}\mathrm{g}}}$

• D

  $2\mathrm{\pi }\sqrt{\frac{\sqrt{3}\mathrm{l}}{\mathrm{g}}}$