A `U`-tube is filled with mercury. When two limbs are maintained at temperatures of `0^(@)C` and `100^(@)C` , then heights of the two columns are `100cm` and `101.8cm` . What is the real coefficient of cubical expansion of mercury ? (Expansion of vessel may be neglected)

Explanation

To find the real coefficient of cubical expansion of mercury, we will follow these steps:

### Step 1: Understand the problem
We have a U-tube filled with mercury, where one limb is at 0°C and the other at 100°C. The heights of the mercury columns are given as 100 cm and 101.8 cm, respectively. We need to find the real coefficient of cubical expansion (γ) of mercury.

### Step 2: Apply pressure equilibrium
Since both limbs are open to the atmosphere, we can use the principle of pressure equilibrium. The pressure at the same horizontal level in both limbs must be equal.

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