Double Slit Spacing B96A4F

1. **State the problem:** We need to find the spacing between adjacent bright fringes in a double-slit experiment. 2. **Formula used:** The fringe spacing $\Delta y$ is given by the formula: $$\Delta y = \frac{\lambda L}{d}$$ where: - $\lambda$ is the wavelength of the light, - $L$ is the distance from the slits to the screen, - $d$ is the distance between the two slits. 3. **Convert units to meters:** - $d = 0.031$ mm = $0.031 \times 10^{-3} = 3.1 \times 10^{-5}$ m - $L = 73$ cm = $0.73$ m - $\lambda = 560$ nm = $560 \times 10^{-9} = 5.6 \times 10^{-7}$ m 4. **Calculate fringe spacing:** $$\Delta y = \frac{5.6 \times 10^{-7} \times 0.73}{3.1 \times 10^{-5}}$$ 5. **Simplify the fraction:** $$\Delta y = \frac{5.6 \times 0.73}{3.1} \times 10^{-7 + 0 - (-5)} = \frac{4.088}{3.1} \times 10^{-2}$$ 6. **Calculate the division:** $$\Delta y = 1.3187 \times 10^{-2} = 0.013187 \text{ m}$$ 7. **Convert to mm:** $$0.013187 \text{ m} = 13.187 \text{ mm}$$ **Final answer:** The spacing between adjacent bright fringes is approximately $13.2$ mm.