Two narrow, horizontal, parallel slits (a distance a = 0.60 mm apart) are illuminated by a beam of 500-nm light as shown in Fig. 40-3. Light that is diffracted at certain angles θ reinforces; at others, it cancels. Find the three smallest values for θ at which 

(a) Reinforcement occurs and 

(b) Cancellation occurs. (See Fig. 40-1.)

Transcribed Image Text:

a (r₁ r₂) Fig. 40-3