$A$ narrow glass capillary tube of radius $1.00 \ mm$ is dipped in a trough containing mercury. The amount by which the level of mercury dips down relative to the normal level outside the tube will be approximately $..... \ mm$.
$[$Surface tension of mercury at room temperature $= 0.465 \ N/m$,density of mercury $= 13.6 \times 10^3 \ kg/m^3$,angle of contact with glass $= 135^{\circ}$,$g = 9.8 \ m/s^2]$

• A
  $2$
• B
  $3$
• C
  $5$
• D
  $8$