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- Homework Statement
- (c) A double slit experiment is conducted using a laser source with a wavelength of 560 nm. As shown in Figure 3(a) on page 4, the two slits are separated by a distance of 2 mm, and a screen is located at 10 m away from the double slit. The laser light is directed normal to the double slit and forms an interference pattern on the screen. The refractive index of air is 1. Figure 3(a) is not drawn to scale.

(i) Calculate the distance between the third and the fifth dark lines of the interference pattern on the screen.

(ii) Calculate the phase difference between the two waves arriving at point Q which is 15 mm away from the centre point 0 on the screen, as shown in Figure 3(a).

(only ii is needed)

- Relevant Equations
- $$Δφ = 2π \frac{L_2 - L_1}{λ}$$

$$Δφ = 2π \frac{L_2 - L_1}{λ}$$

$$Δφ = 2π \frac{\sqrt{0.016^2+10^2}-\sqrt{0.014^2+10^2}}{560*10^{-9}}$$

$$Δφ = 33.659 rad$$Answer = 2.24 rad (unsure if the answer provided is correct/wrong)

$$Δφ = 2π \frac{\sqrt{0.016^2+10^2}-\sqrt{0.014^2+10^2}}{560*10^{-9}}$$

$$Δφ = 33.659 rad$$Answer = 2.24 rad (unsure if the answer provided is correct/wrong)