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COLLEGE PHYSICS II - FINAL EXAMINATION

(answers at bottom of page)

1. In the diagram below there are 3 charges: Q1 = +20 uC; Q2 =-50 uC; Q3 = -10 uC.
a) Calculate the Electric Field at point P.
b) Calculate the work required to move a charge of .002 coulombs from infinity to Point P.

2. A square current loop carries a current of I2 = 40 amperes counterclockwise as shown below. A long straight conductor, carrying a current of 20 amperes is laid on the loop as shown. (The wires are insulated so they do not short out.) Determine the net force on the square loop of wire due to the long straight conductor.

3. An astronomical telescope is made using a objective lens with focal length of 80 cm, and an eyepiece lens with a focal length of 4 mm. What is the magnification and length of the telescope.

4. Red light, of wavelength 660 nm, is incident on a double slit of width .2 mm and produces an interference pattern on a distance screen. If the distance between the 3^rd maximum and 4^th minimum from the central maximum is 3 centimeters, what is the distance from the double slit to the screen?

5. In the diagram below, a converging lens is placed 14 centimeters in front of a concave mirror. The focal lengths of the lens and the mirror are both 8 centimeters. An object is place 16 centimeters in front of the converging lens. The light from the object passes through the lens going to the right, is reflected off the mirror, and passes through the lens going to the left.
a). Use ray tracing to find the location of the final image. B. Calculate the location of the final image
b). Calculate the total magnification. D. State if the final image is real or virtual; upright or inverted

6. A piece of glass is covered with two thin films as shown below. The first film is to be non-reflection for blue wavelength light of 440 nm. The second film is to non-reflecting for red wavelength light of 650 nm. What is the minimum thickness required for each film?

7. A 30^o - 120^o - 30^o glass triangle is shown below. A horizontal ray of light strikes the triangle as shown. The index of refraction of the glass is 1.5. Trace the path of the ray of light through the glass, showing the angles of incidence and refraction as the ray travel through and our of the glass.

1.  E = 5.2. x 10⁷ n/c @ 171.3 deg,  Work = -7.5 x 10³ J; 2. 8.5 x 10^-4 N (left); 3. 200, 80.4 cm; 4.18.2 m; 5. q₃ = 22.5 cm to left of lens, M_total = +1.44; 6. t₁ = 78.6 nm, t₂ = 203 nm; 7. 1st incident angle = 60 deg, 1st refraction angle = 35.3 deg, 2nd incident angle = 5.3 deg, 2nd refraction angle = 8 deg. (beam exits opposite side it entered.)