In a meter bridge, null point is `20 cm`, when the known resistance `R` is shunted by `10 Omega` resistance, null point is found to be shifted by 10 cm. Find the unknown resistance `X`.

Explanation

To solve the problem step by step, we will use the principles of a meter bridge and the concept of shunting resistances.

### Step 1: Understand the Initial Condition
In the initial condition, the null point is at 20 cm on the meter bridge. This means that the ratio of the known resistance \( R \) to the unknown resistance \( X \) can be expressed as:
\[ \frac{R}{X} = \frac{L_1}{100 - L_1} \]
where \( L_1 = 20 \, \text{cm} \).
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