## Question 1

**Which principle states that every point on a wavefront acts as a source of secondary wavelets?**

A. Newton's principle

B. Huygens' principle

C. Doppler's principle

D. Fermat's principle

## Question 2

**The central maximum in a single-slit diffraction pattern is observed to be wider than the subsequent maxima. What is the primary reason for this?**

A. Interference of waves

B. Polarisation of light

C. Dispersion of light

D. Geometry of the slit

## Question 3

**Which of the following factors will increase the width of the central maximum in a single-slit diffraction pattern?**

A. Decreasing the slit width

B. Increasing the frequency of light

C. Decreasing the screen distance

D. Increasing the speed of light

## Question 4

**For a single-slit diffraction pattern, the first minimum occurs when the path difference between waves from the top and bottom of the slit is:**

A. λ/2

B. λ

C. 2λ

D. 3λ/2

## Question 5

**If the wavelength of light used in a single-slit diffraction experiment is doubled, the width of the central maximum will:**

A. Remain the same

B. Halve

C. Double

D. Quadruple

## Question 6

**a)** What is Huygens' principle and how does it relate to diffraction? [3]

**b)** A single slit has a width of 0.5 mm. If monochromatic light of wavelength 650 nm is shone on the slit, what is the width of the central maximum on a screen 1.5 m away from the slit? [4]

## Question 7

**a)** How does the central maxima differ from the subsequent minima in a diffraction pattern? [3]

**b)** For a slit width of 0.2 mm and light of wavelength 500 nm, what is the angle to the first minima in the diffraction pattern? [3]

## Question 8

**a)** How does the width of the central maxima change with an increase in slit width in a single-slit diffraction pattern? [2]

**b)** In a single slit diffraction setup with a slit width of 0.3 mm, how does the width of the central maxima change if the wavelength of the light used is doubled? [3]

## Question 9

**a)** Explain Huygens' principle and its significance in understanding wavefronts. [3]

**b)** A single slit has a width of 0.5 mm. Monochromatic light of wavelength 650 nm is incident on the slit. Calculate the width of the central maximum on a screen placed 1.5 m away from the slit. [4]

**c)** How would the width of the central maximum change if the wavelength of the light used is decreased? [2]

## Question 10

**a)** Describe the difference between the central maxima and the subsequent minima observed in a diffraction pattern. [3]

**b) **What factors determine the position and width of the first minima in a diffraction pattern? [3]

**c)** If the slit width is increased, how does it affect the position of the first minima? [2]