Question

A capillary tube is taken from earth's surface to moon's surface. The rise of liquid column on the moon's surface is (acceleration due to gravity on the earth's surface is six times that of moon's surface)

• A. zero.
• B. six times that on the earth's surface.
• C. equal to that on the earth's surface.
• D. $(\frac{1}{6})^{\text{th}}$ that on the earth's surface.

Hint:

Capillary rise varies inversely with gravity: \[ h\propto \frac{1}{g} \] So smaller \(g\) means larger capillary rise.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Capillary rise is determined by the balance between surface tension forces and gravity.
Step 2: Key Formula or Approach:
$h = \frac{2T \cos \theta}{r \rho g} \implies h \propto \frac{1}{g}$.
Step 3: Detailed Explanation:
Since $g_{moon} = g_{earth} / 6$, the height $h$ is inversely proportional to $g$. Therefore, $h_{moon} = 6 \times h_{earth}$.
Step 4: Final Answer:
The rise is six times that on the earth's surface.