PHYS2386 Tutorial 3 PDF

**PHYS2386 Tutorial 3** 1. A pair of screens are placed 13.7m apart. A third order fringe is seen on the screen 2.50cm from the central fringe. If the slits were cut 0.0960 cm apart, determine the wavelength of this light. Roughly what colour is it? 2. If a yellow light with a wavele...

**PHYS2386 Tutorial 3** 1. A pair of screens are placed 13.7m apart. A third order fringe is seen on the screen 2.50cm from the central fringe. If the slits were cut 0.0960 cm apart, determine the wavelength of this light. Roughly what colour is it? 2. If a yellow light with a wavelength of 540 nm shines on a double slit with the slits cut 0.0100 mm apart, determine what angle you should look away from the central fringe to see the second order fringe? 3. For a single slit experiment, determine how far from the central fringe the first order violet (λ = 350nm) and red (λ = 700nm) colours will appear if the screen is 10 m away and the slit is 0.050 cm wide. 4. A parallel beam of light of 600 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1.2 m away. It is observed that the first minimum is at a distance of 3 mm from the centre of the screen. Calculate the width of the slit. 5. In optics, a wave front is the leading edge of a light wave, and Huygen\'s principle helps us understand how they behave. Imagine a plane wave front approaching a thin convex lens. We will see how this wave front moves through the lens, changes direction, and converges at the lens\'s focal point. a. Define the term wave front. b. State Huygen's principle. c. Consider a plane wave front incident on a thin convex lens. Draw a diagram to show how the incident wave front traverses through the lens, and after refraction focusses on the focal point of the lens, giving the shape of the emergent wave front.