Question

The angular size of the central maxima due to a single slit diffraction (a = slit width) is:

• A. \(\dfrac{\lambda}{a}\)
• B. \(\dfrac{2\lambda}{a}\)
• C. \(\dfrac{3\lambda}{2a}\)
• D. \(\dfrac{\lambda}{2a}\)

Hint:

Angular width of central maximum equals angle between first minima on either side.

Answer 1

The Correct Option is A

Step 1: First minima occurs when: \[ a\sin\theta=\lambda \]
Step 2: For small angles: \[ \theta \approx \frac{\lambda}{a} \]