HSC Physics Interference of Waves

A tutorial sheet on double slit interference is given below.

1. Coherent, monochromatic light passes through a single narrow rectangular slit. Describe the intensity pattern that forms on a screen at a large distance from the slit.
2. Coherent, monochromatic light passes through two parallel narrow rectangular slits. Describe the intensity pattern that forms on a screen at a large distance from the slits.
3. Coherent red light of wavelength 650 nm passes through a double slit of separation 0.2 mm. Determine the distance between successive bright fringes on a screen 3.0 m from the double slit.
4. What is the path difference when the first order maximum forms on a screen?
5. In a double slit experiment one of the slits is covered up. Is the central maximum brighter when one of the slits is covered?
6. Microwaves have a wavelength of 3.0 cm. A micowave detector is placed alongside the microwave source. The microwaves are aimed perpendicular at thin parallel perspex and metal sheets. Some microwaves reflect back from the perspex and all are reflected back by the metal sheet. What is the least distance between the sheets when constructive interference occurs in the reflected microwaves?