PHYSICS 7C Midterm: physics7C-sp2017-mt2-Stahler-soln

6 views8 pages

turquoisegnu128

8 Jan 2019

School

Department

Course

Professor

For unlimited access to Study Guides, a Grade+ subscription is required.

Document Summary

Figure 1: view of polaroid placement, looking in + y-direction, part (a). (a) after the initial unpolarized light passes through polaroid a, the intensity will reduce by half: 2 and the light between a and c will be polarized vertically (along the z-direction). If the polarization axis of c is at angle c to the polarization axis of a, the intensity ic will be: Since the angle between the axes of a and b is . 2 , the angle between c and b is . 2 ) = sin and use a double angle identity to say that. 2 c) cos2 c sin2 c = cos2( c) cos2( Since the sin function is maximal when its argument is . 2 , the maximum for or c = The value for c can also be found by setting the derivative of if /i0 (with respect to c) equal to zero. d(if /i0) d c.

Related Questions

1)how is the polarization of an electromagnetic wave defined?

a.none of these choices.

b. the polarization is defined by the plane in which the magnetic field is oscillating.

c. the polarization is defined by the direction the wave is traveling.

d. the polarization is defined by the plane in which the electric field is oscillating.

2)In this lab you will be given two polaroid sheets with unlabeled transmission axes. How can you tell, when looking through both polaroid sheets at the same time, if the transmission axes are crossed?

a.If the transmission axes are crossed, you will see one bright line when you look through the polaroid sheets.

b.If the transmission axes are crossed, it will be bright when you look through the polaroid sheets.

c.If the transmission axes are crossed, you will see a bright "+" shape when you look through the polaroid sheets.

d.If the transmission axes are crossed, it will be very dark when you look through the polaroid sheets.

3)In the polarizer + analyzer experiment you will want to start with the transmission axes of the polarizer and the analyzer aligned. How will you know when the transmission axes are aligned?

a.The reading on the detector will be a maximum.

b.The reading on the detector will be a minimum.

c.The 0 degrees reading on the analyzer will be pointing up.

4)Suppose you are wearing polarized sunglasses and looking at a lake on a bright, sunny day. What will happen if you rotate your polarized sunglasses by 90 degrees?

a.The lake will appear equally bright as before you rotated your sunglasses.

b.The lake will appear significantly brighter.

c.The lake will appear significantly darker.

5)Suppose you are looking at unpolarized light coming from an incandescent light bulb. How much will the light intensity you observe be reduced if you look through a single polarizer?

a.50%

b.75%

c.100%

d.25%

peachgrasshopper627

DUE DATE: 12 00 noon Monday. Dec 6. 2010. The problems on this assignment are quite word because strong direction is being given to Students in how to proceed. Two problems will be selected at random for marking. Percentage polarization. It is useful to characterize partially polarized light in terms of its "percentage polarization". A light beam of constant intensity Io. is allowed to fall at normal incidence on an "ideal linear polarizer" (a linear polarizer is "ideal" if it panes all light polarized parallel to the polarizer's axis, and stops all light polarized perpendicular to that axis.) As the ideal polarizer is rotated continuously (see Figure 8.1; about an axis perpendicular to its plane, the transmitted intensity I passes through successive maximum and minimum values (denoted by I max and I min). The percentage polarization of the incident light is denned to be Find the percentage polarization measured in this way for the following light beams: "Unpolarized natural light" tor which I max = I min = Io/2. A beam of light. Initially unpolarixed. that has been passed through an ideal linear polarizer before being measured for percentage polarization. A beam of light, initially unpolarizcd, that has been passed through a non-ideal polarizer that (in terms of light intensity) transmits 70% of light polarized parallel to its polarizing axis and 20% of light polarized perpendicular to its polarizing axis. Circularly polarized light. (Circular polarization means that at any given fixed observation point In the beam, the E-vector has constant magnitude but rotates at the frequency of the electric field oscillations so that the tip of the vector describes a circle in the zy plane (perpendicular to the light ray at the point in question). Elliptically polarized light for which the tip of the E-vector moves on an ellipse in the x y plane, defined by where Ax and Ay are the amplitudes of the oscillating Ex and E y components of the electric field vector, and is the phase difference between those oscillations. NOTE: Do your calculation for the special case Ax = 2Ay and e =pi / 2. [(8.2) taxes a particularly simple form when e = pi / 2.]

a. Is the light of the Sun Polarized?

b. The light emitted by the Sun is mostly yellow so that its wavelength is about 550 nm. What is its frequency?

c. The distance between the Earth and the Sun is about 149 million kilometers. How long does it take for the light to travel this distance?

d. A polarizer is placed in the xy-plane. Its polarization axis coincides with the x-axis. The z-axis is taken as the line of sight when looking at the Sun. What is the direction of the transmitted light electric field? What is the direction of the transmitted magnetic field? Sketch the direction of light propagation, the direction of the electric field, and the direction of the magnetic field of the transmitted light.

e. The intensity per unit we receive from the sun is about1413W/m^2. What is the intensity of the transmitted light after the polarizer?

f. If you could look only at the light after it had been reflected, say, by the sea (and NOT AT ALL at the direct radiation), what would you see?

blushbeaver438

PHYSICS 7C Midterm: physics7C-sp2017-mt2-Stahler-soln

Document Summary

Get access

Related textbook solutions

Physics: Principles with Applications

Related Documents

PHY 2020 Lecture Notes - Lecture 41: Transverse Wave, Electric Field, Polarizer

PHY136H5 Lecture Notes - Optical Axis, Electric Field, Black Rod

PHY136H5 Lecture Notes - Electric Field, Polarizer, Cytochrome C Oxidase Subunit I

Related Questions