Question

m-2 m= 1 m=2 mA screen Figure 2. Description of a double slit interference pattern. Peaks represent bright spots. Th when the distances from the first slit to the screen and the second slit to the screen differ by a e constructive interference nd slit to the screen differ by a whole wavelength to the screen, D, is much greater than le. The two angles labeled theta can be considered equal when the distance whole wave multipl the slit separation. What causes the bright and dark fringes to appear on the screen in a double slit interference experiment? Q7. From the diagram in Figure 2 write down the trigonometric e quation that relates slit separation, d, the angle, ?, the wavelength of the light, ?, and the order, m. to the screen, D, and the distance from the center of the pattern to the mth maximum, y. Q9. Using your answers from questions 7-8, derive an approximate formula for the slit separation, d, in Q8. From the diagram in Figure 2 write down an expression for tan 0 in terms of the distance from the slits terms of D, y, ?, and m, what approximation did you make? >Q10. Why is this equation very similar to the one describing diffraction?

Answer 1

If two or more waves travels in phase and superimposed, then the resulting wave have the amplitude greater than the individual wave. It is called the constructive interference. The constructive interference causes the bright fringes If two or more waves travel in out of phase and superimposed, then the resulting wave have the amplitude less than the individual wave. It is called the destructive interference. The destructive interference causes the dark fringes