Physics 202 MWF 10:20 Spring 2001 (Ford)
Exan III Chapts. 23--26 in Cutnell and Johnson 4e
Multiple choice questions. Circle the correct answer. No work need be shown and no partial credit will be given.
(4 pts) 1. Consider the circuit shown in the sketch. When the frequency of the ac generator is very small, the current amplitude through the gnerator is
(a) zero
(b) 2 A
(c) 3 A
(d) 4 A
(e) 5 A
(f) 6 A
(g) infinite
(4 pts) 2. Consider the circuit shown in the sketch. Note that the circuit contains no inductor. Which statement is correct
(a) the current lags the source voltage
(b) the current leadsthe source voltage
(c) the current is in phase with the source voltage
(3 pts) 3. Consider the circuitshown in the sketch. The rms voltage across the resistor is VR = 30 V, the rms voltage across the capacitor is VC = 90 V, and the rms voltage across the inductor is VL = 50 V. What is the rms voltage of the generator?
(a) 50 V
(b) 70 V
(c) 100 V
(d) 140 V
(e) 170 V
(f) 340 V
(3 pts) 4. An object is placedto the left of a spherical mirror. The image formed by the mirror is real. The image is
(a) upright
(b) inverted
(c) could be either upright or inverted
(3 pts) 5.An astronomical telescope is composed of two converging lenses. The focallength of the objective lens is 40 cm and for ease of viewingm the image of the eyepeiceism at infinity. The length of the telescope (distance between the two lenses) is 44 cm. The focal length of the eyepiece lens is
(a) 2 cm
(b) 4 cm
(c) 6 cm
(d) 8 cm
(e) 10 cm
(f) 12 cm
(3pts) 6. The left eye of a medical student has a far point of 2.0 m. The contactlens that will allow this person to fopcus clearly on a distant object is which kind of lens:
(a) converging
(b) diverging
Show all your work. Partial credit will be given if earned. Write your
answers in the blanks provided.
(10 pts) 7. Unpolarized light of intensity S0 = 300 W/m2 is incident on two polarizing filters. The axis of the first filter is at 30° with respect to the vertical. The axis of the second filter is at 67° with respect to the vertical. What is the intensity of the light after it has passed trhough the second filter?
Ans. ______________
(14 pts) 8. A square block of glass with refractive index 1.60 is immersed in a liquid. If a ray of light traveling in the glass is incident at the glass-liquid interface at an angle with respect to the normal to the glass surface greater than 75° none of the light is refracted into the liquid. What is the speed of the light in the liquid?
Ans. ________________
(18 pts) 9. An object is to the left of a spherical mirror that has focal length f = +40 cm. The magnification is m = +2.0.
a) How far is the object from the mirror?
Ans.____________
b) Is the image real or virtual?
Ans.______________
(18 pts) 10. An ac circuit consists of a resistor in series with a capacitor and an ac generator that supplies an rms voltage of 240 V. There is no inductor in the circuit. At the frequency of the generator the reactance of the capacitor is 50 
. The rms current in the circuit is 3.0 A. What is the average power supplied by the generator?
Ans.___________________
(20 pts) 11. An object 2 mm tall is placed 36.0 cm to the left of a diverging lens that has focallength f = - 12.0 cm. A second lens is placed 3.0 cm to the right of the first lens. The final image is 30.0 cm to the left of the second lens.
a) Is the final image real or virtual?
Ans.___________________
b)What is the focal length of the second lens and is this lens converging or diverging?
Ans. f = ___________
converging or diverging? ______________
c) What is the height and orientation (upright or inverted) of the final image?
Ans. height ______________
orientation? _______________