Physics II

Time and Date Stamps (logged): 03:42:12 08-29-2008 ｯｲ浹ｱ涓ｱｯｷ浤ｸ浤ｯｯｷ Physics II

Principles of Physics (Phy 122) Test_4

Completely document your work and your reasoning.

You will be graded on your documentation, your reasoning, and the correctness of your conclusions.

** Write clearly in dark pencil or ink, on one side of the paper only. **

10-03-2001 20:45:48

Test should be printed using Internet Explorer. If printed from different browser check to be sure test items have not been cut off. If items are cut off then print in Landscape Mode (choose File, Print, click on Properties and check the box next to Landscape, etc.).

Name and Signature of Student _____________________________

Signed by Attendant, with Current Date and Time: ______________________

If picture ID has been matched with student and name as given above, Attendant please sign here: _________

Instructions:

Test is to be taken without reference to text or outside notes.
Graphing Calculator is allowed, as is blank paper or testing center paper.
No time limit but test is to be taken in one sitting.
Please place completed test in Dave Smith's folder, OR mail to Dave Smith, Science and Engineering, Va. Highlands CC, Abingdon, Va., 24212-0828 OR email copy of document to dsmith@vhcc.edu, OR fax to 276-739-2590. Test must be returned by individual or agency supervising test. Test is not to be returned to student after it has been taken. Student may, if proctor deems it feasible, make and retain a copy of the test..

Directions for Student:

Completely document your work.
Numerical answers should be correct to 3 significant figures. You may round off given numerical information to a precision consistent with this standard.
Undocumented and unjustified answers may be counted wrong, and in the case of two-choice or limited-choice answers (e.g., true-false or yes-no) will be counted wrong. Undocumented and unjustified answers, if wrong, never get partial credit. So show your work and explain your reasoning.
Due to a scanner malfunction and other errors some test items may be hard to read, incomplete or even illegible. If this is judged by the instructor to be the case you will not be penalized for these items, but if you complete them and if they help your grade they will be counted. Therefore it is to your advantage to attempt to complete them, if necessary sensibly filling in any questionable parts.
Please write on one side of paper only, and staple test pages together.

Test Problems:

. . . . . . . . . . . . . . . .

Constants

Constants:

k = 9*10^9 N m^2 / C^2	qE = 1.6 * 10^-19 C	h = 6.63 * 10^-34 J s
energy of n=1 orbital in hydrogen atom: -13.6 eV	k ' = 9 * 10^-7 T m / amp	atomic mass unit: 1.66 * 10^-27 kg
electron mass: 9.11 * 10^-31 kg	speed of light: 3 * 10^8 m/s	Avogadro's Number: 6.023 * 10^-23 particles/mole
Gas Constant: R = 8.31 J / (mole K)	proton mass: 1.6726 * 10^-27 kg	neutron mass: 1.6749 * 10^-27 kg

Problem Number 1

A photon of 95.28419 nm electromagnetic radiation encounters an electron in the n = 2 orbital of a hydrogen atom, and causes it to 'jump' to the n = 3 orbital. What will be the wavelength of a photon which carries away any excess energy from the collision?

Problem Number 2

What will be the force on a segment of wire 13 cm long, carrying a current of 15 amps, in the presence of a .0079 Tesla magnetic field directed perpendicular to the segment? If the current is directed toward the North and the magnetic field vertically upward, what will be the direction of this force?

Problem Number 3

What is the flux of a magnetic field of magnitude 2.5 Tesla through a square loop with side 6.6 meters, if the field is perpendicular to the plane of the loop?

Problem Number 4

A beam of protons, each with rest mass about 1.6 * 10^-27 kg, are accelerated to near-light-speed velocities before entering a magnetic field of .6 Tesla. The magnetic field is directed perpendicular to the direction of the beam. Without taking account of the relativistic effect on mass, what should be the radius of curvature the protons if they are moving at 2.56 * 10^8 m/s as the beam passes through the magnetic field?

What should be the radius of curvature of the beam if we take relativistic effects into account?

What will happen to the radius of curvature as the velocities of the protons approach the speed of light?

Problem Number 5

A beam consisting of 90 eV electrons (electron mass 9.11 * 10^-31 kg) is incident on a thin wafer of a crystal with layer spacing 2.8 Angstroms. Surprisingly we find that the electrons, which are particles, are scattered in such a way as to form an interference pattern identical to that of a wave. What will be the distance between central interference maxima at a distance of 10 cm from the wafer?

Problem Number 6

Find the magnitude of the magnetic field due to a straight current segment of length .062 m, at a distance of 8.2 meters from the segment, given that the vector from the midpoint of the segment to the point makes at angle 55 degrees with the segment, and that a current of .1 Amps flows in the segment.