Total no of lines in Lyman series of H spectrum will be-
(where n=no. of orbits)

Options

A. `n`
B. `n-1`
C. `n-2`
D. `n(n+1)`

Answer

To find the total number of lines in the Lyman series of the hydrogen spectrum, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Lyman Series**:
The Lyman series corresponds to electronic transitions in hydrogen where the electron falls to the first energy level (n=1). The transitions can occur from higher energy levels (n=2, 3, 4, ...) down to n=1.

2. **Identifying the Energy Levels**:
Let’s denote the initial energy level as \( n \) (where \( n \) can be any integer greater than or equal to 2) and the final energy level as \( n' = 1 \) (the ground state).

3. **Calculating the Number of Transitions**:
The number of possible transitions from a level \( n \) to the level \( n' = 1 \) can be calculated as follows:
- From \( n=2 \) to \( n=1 \)
- From \( n=3 \) to \( n=1 \)
- From \( n=4 \) to \( n=1 \)
- ...
- From \( n=n \) to \( n=1 \)

This means that for each energy level \( n \), there are \( n-1 \) possible transitions (since you can transition from levels \( n \) down to 1).

4. **Total Number of Lines**:
Therefore, the total number of lines in the Lyman series can be calculated using the formula:
\[ \text{Total number of lines} = n - 1 \]
where \( n \) is the number of the highest energy level from which the electron can transition down to the ground state.

5. **Conclusion**:
Thus, the total number of spectral lines in the Lyman series of the hydrogen spectrum is \( n - 1 \).

### Final Answer:
The total number of lines in the Lyman series of the hydrogen spectrum will be \( n - 1 \).

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