In YDSE, `d=5lambda`, then the total no. of maxima observed upon screen will be

Options

A. 9
B. 8
C. 7
D. 5

Answer

To solve the problem of finding the total number of maxima observed on the screen in Young's Double Slit Experiment (YDSE) when the distance between the slits \( d = 5\lambda \), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the relationship between distance and wavelength**:
In YDSE, the distance between the slits \( d \) is related to the wavelength \( \lambda \) of the light used. The formula for the number of fringes (maxima) is given by:
\[ n = \frac{d}{\lambda} \]

2. **Substitute the given values**:
We know from the problem that \( d = 5\lambda \). Substituting this into the formula gives:
\[ n = \frac{5\lambda}{\lambda} \]

3. **Simplify the expression**:
Canceling \( \lambda \) from the numerator and denominator, we find:
\[ n = 5 \]

4. **Calculate the total number of maxima**:
The total number of maxima observed on the screen can be calculated using the formula:
\[ \text{Total maxima} = 2n - 1 \]
Substituting \( n = 5 \) into this formula:
\[ \text{Total maxima} = 2 \times 5 - 1 = 10 - 1 = 9 \]

5. **Conclusion**:
Therefore, the total number of maxima observed on the screen is:
\[ \text{Total maxima} = 9 \]

### Final Answer:
The total number of maxima observed upon the screen is **9**.

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