(896) Problem 7: A laser beam is incident on two slits with separation d= 0.012

Question

(896) Problem 7: A laser beam is incident on two slits with separation d= 0.012 mm. A screen is placed L = 1.2 m from the slits. The wavelength of the laser light is 1250 1 and 2 are the angles to the first and second bright fringes above the center of the screen ©theexpertta.com Solve for the numerical value ofy, the distance between the two bright fringes on the screen, in meters Grade Summa Deductions Potential ry 0% 100% sinO cotan0asin acos0 atan0 acotan) sinh0 cosh0 tanh cotanh0 cos0 tan Submissions Attempts remaining: 4 (090 per attempt) detailed view *12 3 END Degrees Radians NO Submit Hint Hints: 5% deduction per hint. Hints remaining: 3 Feedback: 0% deduction per feedback.

Explanation / Answer

The condition for bright fringes is d*sin(theta) = m*lamda

d = 0.012*10^-3 m

since theta_1 is small

then

sin(theta_1) = tan(theta_1) = R/L

sin(theta_2) = tan(theta_2) = (R+y)/L

then using d*sin(theta_1) = 1*lamda

and also d*sin(theta_2) = 2*lamda

sin(theta_1)/sin(theta_2) = 1/2

(R/L) / [(R+y)/L] = 1/2

(R+y)/R = 2

1+(y/R) = 2

y/R = 2-1= 1

R = y

then

sin(theta_2) = (y+y)/L = 2*lamda/d

2*y/L = 2*lamda/d

y = lamda*L/d

y = (1250*10^-10*1.2)/(0.012*10^-3) = 0.0125 m

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.