EXAMPLE QUESTIONS 1. Under normal conditions a diode does not conducts current when it is A) reverse-biased. B. forward-biased. C. avalanched. D. saturated. 2. The movement of holes in a conductor is called A. voltage. B. current.. C. recombination. D. equilibrium. 3. Which statement best describes a semiconductor? A. A material with many free electrons. B. A material doped to have some free electrons. A material with few free electrons. No description fits. 4. Silicon uses four electrons to form bonds with adjacent silicon atoms. If silicon atoms are replaced with atoms with three electrons for bonding, this produces: A. a pn junction. B. a p-type material. C. a n-type material. D. faster electrons. 5. An ideal diode presents a(n) biased. A. open, short B short, open C. open, open D. short, short connected to the positive side of the source, connected to the negative side of the source. 6. A forward-biased diode has the and the when forward-biased and a(n)_when reverse- A. cathode, anode B. cathode, base C. base, anode D. anode, cathode 7. A P-N junction mimics an closed switch when it: A has a low junction resistance B. is reverse biased C. cannot overcome its barrier voltage D. has a wide depletion region 8. When transistors are used in digital circuits they usually operate in the A active region B. breakdown region C. saturation and cutoff regions D. linear region 9. A transistor may be used as a variable resistor or as a A fixed resistor v.3 B. tuning device C. rectifier D) switching device 10. For the circuit at the right, the switch is closed to charge the capacitor to 9V and then opened to discharge the capacitor through the resistor R. If the time constant (tau) is 10 seconds for the exponential decay, determine the value for C in microfarads. Q=CV 1002 Carl = (22 x 10F)V. 11. A 22 microfarad capacitor is charged until stores 0.002 C. Calculate the voltage across the capacitor. 12. A stretched string of length L = 6 m resonates in three loops. What is the wavelength of the wave? A. 001111-1S B. 010111 001100- 23722 D. 101010 A. 1 m B. B. 2 m C. C. 3 m D. D. 4 m E. E. 6m 13. The base-2 representation for the base-10 number 12 is: 01||| =9V L B. A = 0, B = 0, C = 1 C. A = 1, B = 1, C = 1 D. A = 1, B = 0, C = 0 R-50K V L 14. The output of an AND gate with three inputs, A, B, and C, is HIGH when A. A = 0, B=0, C = 0 .002 22x10-6 = 90.90 0.21 0.2 +1-2 +1.2 +1-2 H-2 3 15. The output of a NOR gate is LOW if A. all inputs are HIGH any input is HIGH C. any input is LOW D. all inputs are LOW v.3 16. The format used to present the logic output for various combinations of logic inputs is called a(n). A. Boolean constant B. Boolean variable C. truth table D. input logic table 17. Warren Marrison used this knowledge to create a clock that kept time by counting the vibrations of a mineral crystal. What was the mineral that in 1969 was also used to regulate the time the world's first electronic wristwatch? A. Pendulite B. Cesium crystal Quartz D. Regulite NOR Gole 18. Which chemical element has a resonant state that is used in the atomic clock that is used to define the standard second? A. Hydrogen. B. Cesium C. Rubidium D. Mercury 19. Why does the shadow on a sun dial move in a "counter clockwise" direction in the Southern Hemisphere? A. Because the gears the gears turn that direction. B. Because electrons are right-handed. C. Because Galileo made his first clock to turn that way. Shadow on a sun dial rotates that way. 20. If a 3-input NOR gate has eight binary input possibilities, how many of those possibilities will result in a HIGH output? A. 1 B. 2 C. 3 D. 4