# HW 40 - terry(ect328 – homework 40 – Turner –(59130 1...

This preview shows pages 1–3. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: terry (ect328) – homework 40 – Turner – (59130) 1 This print-out should have 10 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Consider the setup of a single slit experiment. The wavelength of the incident light is λ = 550 nm . The slit width and the distance between the slit and the screen is specified in the figure. y 1 7 . 5 m 860 μ m S 1 S 2 θ viewing screen Find the position y = y 1 of the first inten- sity minimum. Use a small angle approxima- tion sin θ = tan θ . Correct answer: 4 . 79651 mm. Explanation: Let : λ = 550 nm , L = 7 . 5 m , and a = 860 μ m . y 1 L a S 1 S 2 θ viewing screen δ ≡ a sin θ ≈ a bracketleftBig y L bracketrightBig For single slit diffraction, destructive in- terference occurs when, a 2 sin θ = λ 2 , or sim- ply when, δ ≡ a sin θ = λ . Thus, between the two end rays which correspond to the first minimum, the phase angle difference is β 1 = 2 π and the path length difference is δ 1 = λ . The small angle approximation gives us y 1 L = tan θ 1 ≈ θ 1 ≈ sin θ 1 = δ 1 a , or y 1 = δ 1 a L = λ L a = sturt 4 . 79651 mm . 002 10.0 points Consider the setup of a single slit experiment. y 3 L a S 1 S 2 θ viewing screen × 15 Find the height y 3 where the third mini- mum occurs. Use a small angle approxima- tion sin θ = tan θ . 1. y 3 = 7 2 λ L a 2. y 3 = 3 λ L a correct 3. y 3 = 1 λ L a 4. y 3 = 5 2 λ L a 5. y 3 = 11 2 λ L a 6. y 3 = 5 λ L a 7. y 3 = 4 λ L a 8. y 3 = 9 2 λ L a 9. y 3 = 3 2 λ L a 10. y 3 = 2 λ L a Explanation: Let : k ≡ 2 π λ . terry (ect328) – homework 40 – Turner – (59130) 2 The first minimum is at β = 2 π , where β = 2 φ = 2 π , and φ = π is the phase difference of the two rays for destructive interference....
View Full Document

## This note was uploaded on 02/17/2010 for the course PHY 59130 taught by Professor Turner during the Fall '09 term at University of Texas.

### Page1 / 5

HW 40 - terry(ect328 – homework 40 – Turner –(59130 1...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online