# 21_3 answers

## 21_3 answers

**Number 1**

In a two slit interference experiment the third order interference maximum occurs under the same angle as the first order diffraction minimum. If the slit distance is 0.1504 mm what is the slit width (sheet 26,28) ? Indicate with a negative (positive) sign whether there is always (only sometimes) single slit diffraction present in a 2 slit interference experiment.

.1504E-3 * (1/3) = .0000501333

answer is negative

**Number 2**

In 10 slit interference the slit distance is 0.0735 mm and the wavelength is 497 nm. Under which angle (in degrees) does the 4th order interference maximum occur (sheet 28') ? Indicate with a negative (positive) sign whether the interference maxima for 10 slit interference are narrower (wider) than the maxima for 2 slit interference.

(497E-9 * 4) / .0735E-3 = .0270476

sin-1 (.0270476) = 1.549903

anwer is negative

**Number 3**

A diffraction grating has 14.72 10^3 lines per cm. What is the slit distance (see sheet 31) ? Indicate with a positive (negative) sign whether the interference maxima for the diffraction grating are narrower (wider) than the maxima for 10 slit interference.

.01 / 14.72E3 = 2.34907E-7

answer is positive

**Number 4**

Consider diffraction of 519 nm wavelength light on a circular aperture with a 0.2844 mm diameter. Under which angle in degrees does the edge of the central maximum (of the diffraction disk) occur ? (see sheet 33. Use the small angle approximation as in (21.10). The angle in (21.10) is in radians !) Indicate with a negative (positive) sign whether diffraction limits (enhances) the resolution of optical instruments.

1.22 * (519E-9 / .2844E-3) = .00222637

.00222637 * (180 / pi) = .127561679

answer is negative

**krolik**- Guest

## Question 3

Correct solution for Question 3:

That gives our answer in centimeters. Convert this to meters. That is the final answer.

A explanation is on sheet 31 of the CD.

**(number given)^-1**That gives our answer in centimeters. Convert this to meters. That is the final answer.

A explanation is on sheet 31 of the CD.

**DJ**- Guest

## Re: 21_3 answers

to DJ

when I use this #

that's what i am getting

(14.72 10^3)^-1 equal 6.75E-5 and it says thats wrong

when I use this #

that's what i am getting

(14.72 10^3)^-1 equal 6.75E-5 and it says thats wrong

**mem**- Guest

## RE: Question 3 (for 'mem')

You have to convert that value, which is in centimeters, to meters (SI units).

So, your answer would be:

So, your answer would be:

**6.79347826 × 10-7 meters**. That should work.**DJ**- Guest

## Re: 21_3 answers

do it ag wrote:the solution for question 3 works you morons!!!

It certainly didn't before.

So, now you have two working solutions. Enjoy.

**DJ**- Posts : 28

Join date : 2009-03-17

Page

**1**of**1****Permissions in this forum:**

**cannot**reply to topics in this forum