Assertion (A) : Limiting line is the balmer series ghas a wavelength of `364.4 nm`
Reason (R ) : Limiting line is obtained for a jump electyron from `n = prop`

Options

A. If both (A) and (R ) correct and (R ) is the correct explanation for (A)
B. If both (A) and (R ) correct and (R ) is the correct explanation for (A)
C. If (A) is correct but (R ) is incorrect
D. If (A) is incorrect but (R ) is correct

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the limiting line of the Balmer series has a wavelength of 364.4 nm.
- The Balmer series corresponds to electronic transitions in hydrogen where the electron falls to the n=2 energy level from higher energy levels (n=3, 4, 5, ...).

2. **Identifying the Limiting Line**:
- The limiting line in the Balmer series occurs when the electron transitions from an infinitely high energy level (n=∞) to the n=2 level.
- This transition results in the emission of a photon with a specific wavelength.

3. **Using the Rydberg Formula**:
- The Rydberg formula for the wavelength (λ) of the emitted light is given by:
\[ \frac{1}{\lambda} = R \left( \frac{1}{n_1^2} - \frac{1}{n_2^2} \right) \]
- For the limiting line of the Balmer series, we set \( n_1 = 2 \) and \( n_2 = \infty \):
\[ \frac{1}{\lambda} = R \left( \frac{1}{2^2} - 0 \right) = R \left( \frac{1}{4} \right) \]

4. **Calculating the Wavelength**:
- Rearranging gives us:
\[ \lambda = \frac{4}{R} \]
- The Rydberg constant \( R \) is approximately \( 1.097 \times 10^7 \, \text{m}^{-1} \).
- Substituting the value of \( R \):
\[ \lambda = \frac{4}{1.097 \times 10^7} \approx 364.4 \, \text{nm} \]
- This confirms that the limiting line of the Balmer series indeed corresponds to a wavelength of 364.4 nm.

5. **Understanding the Reason**:
- The reason states that the limiting line is obtained for a jump of the electron from \( n = \infty \).
- This is correct, as we have established that the limiting line occurs when the electron transitions from an infinitely high energy level to the n=2 level.

6. **Conclusion**:
- Both the assertion and the reason are correct. The reason correctly explains the assertion.

### Final Answer:
Both the assertion (A) and the reason (R) are correct, and the reason is the correct explanation for the assertion.