09HW10 - Niu (qn269) Homework #10 antoniewicz (58855) 1...

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

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Niu (qn269) Homework #10 antoniewicz (58855) 1 This print-out should have 17 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points An unpolarized light beam with intensity of I passes through 2 polarizers shown in the picture. Transmission axis Polarized lihgt Polarizer Analyzer Unpolarized light E E cos If = 30 ,what is the beam intensity after the second polarizer? 1. I 2 = 3 16 I 2. I 2 = 5 8 I 3. I 2 = 1 4 I 4. I 2 = 3 8 I correct 5. I 2 = 7 16 I 6. I 2 = 1 16 I 7. I 2 = 9 16 I 8. I 2 = 1 8 I 9. I 2 = 5 16 I 10. I 2 = 1 2 I Explanation: The beam intensity after the first polarizer is I 1 = I 2 . We use the formula for the intensity of the transmitted (polarized) light. Thus the beam intensity after the second polarizer is I = I 1 cos 2 = I 2 cos 2 (30 ) = 3 I 8 002 (part 1 of 3) 6.0 points White light is incident normally on a trans- mission grating and the spectrum is observed on a screen 4 m from the grating. In the second-order spectrum, the separation be- tween light of 520 nm wavelength and 590 nm wavelength is 11 . 9 cm. Determine the number of lines per centime- ter of the grating. Correct answer: 2125 cm 1 . Explanation: Let : y = 11 . 9 cm = 0 . 119 m , L = 4 m , 1 = 520 nm , and 2 = 590 nm . 1 2 L y 1 y 2 The grating equation is d sin = m, where m = 0 , 1 , 2 , ... Assuming 2 0 and m = 2, we have sin 2 tan 2 = y L . Substituting, d y L = m y = mL d , Niu (qn269) Homework #10 antoniewicz (58855) 2 so the separation between light of 1 wave- length and 2 wavelength is y = mL 2 d- mL 1 d = mL d ( 2- 1 ) So d = mL ( 2- 1 ) y The number of lines per centimeter of the grating is N = 1 d = y mL ( 2- 1 ) = . 119 m 2 (4 m) (590 nm- 520 nm) 10 9 nm 10 2 cm = 2125 cm 1 . 003 (part 2 of 3) 2.0 points What is the separation between these two wavelengths in the first-order spectrum? Correct answer: 5 . 95 cm. Explanation: Let : N = 2125 cm 1 = 2 . 125 10 5 m 1 . The separation of the wavelengths is y = mL ( 2- 1 ) d = mLn ( 2- 1 ) , so for m = 1 , y = Ln ( 2- 1 ) = (4 m) (2 . 125 10 5 m 1 ) (590 nm- 520 nm) 10 2 cm 10 9 nm = 5 . 95 cm . 004 (part 3 of 3) 2.0 points What is the separation between these two wavelengths in the third-order spectrum?...
View Full Document

This note was uploaded on 11/18/2009 for the course PHY 58855 taught by Professor Antoniewicz during the Spring '09 term at University of Texas at Austin.

Page1 / 7

09HW10 - Niu (qn269) Homework #10 antoniewicz (58855) 1...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online