Question

Consider two statements given below: Statement-I: In YDSE, if distance between slits \& screen increases, fringe width also increases. Statement-II: If wavelength of light used in YDSE increases, fringe width also increases. Which of the following options is correct?

• A. Both statements I \& II are correct
• B. Statement I is correct but statement II is incorrect
• C. Statement I is incorrect but statement II is correct
• D. Both statements I \& II are incorrect

Hint:

In Young's Double Slit Experiment (YDSE), fringe width is proportional to both the wavelength of light and the distance between the slits and the screen.

Answer 1

The Correct Option is A

Step 1: Understand the relationship between fringe width and distance.
In Young's Double Slit Experiment (YDSE), the fringe width \( \beta \) is given by the formula: \[ \beta = \frac{\lambda D}{d} \] where: - \( \lambda \) is the wavelength of light, - \( D \) is the distance between the slits and the screen, - \( d \) is the distance between the slits. - Statement I: If the distance between the slits and the screen increases, then the fringe width increases, as \( \beta \) is directly proportional to \( D \).
Step 2: Understand the relationship between fringe width and wavelength.
- Statement II: The fringe width is directly proportional to the wavelength \( \lambda \), so if the wavelength of light used in YDSE increases, the fringe width also increases. Both statements are correct based on the relationships derived from the fringe width formula. Thus, the correct answer is (1) Both statements I \& II are correct.