Red laser light is incident on a double-slit and an interference pattern appears on a screen 2 m away.
(a) Describe what we mean by saying "an interference pattern appears" ?
(b) What is the path-length difference for the two beams that arrive at the m = 2 bright spot?
(c) What would happen to the spacing (the distance) between bright spots if we replace red light with blue light?
(d) What would happen to the spacing (the distance) between bright spots if we replace move the screen to 4 meters away?
(e) What would happen to the spacing (the distance) between bright spots if we replace the red laser light with an incandescent light bulb (where tungsten "glows" to provide incoherent light)?