Chapter 7 SPECIAL SOLID STATE DEVICES MCQs 20 min Score: 0 Attempted: 0/20 Subscribe 1. .1 A UJT has (A) Two PN junctions (B) One PN junction (C) Three PN junctions (D) None of the aboveShow All Answers 2. .2 In a UJT, the p-type emitter is (A) Lightly doped (B) None of the above (C) Moderately doped (D) Heavily dopedShow All Answers 3. .3 Internally UJT acts as? (A) Inductance divider (B) Capacitance divider (C) Voltage divider (D) Current dividerShow All Answers 4. .4 When the emitter terminal of a UJT is open; the resistance between the base terminals is generally (A) High (B) Low (C) Extremely low (D) None of the aboveShow All Answers 5. .5 When a UJT is turned ON, the resistance between emitter terminal and lower base terminal (A) Is decreased (B) Remains the same (C) Is increased (D) None of the aboveShow All Answers 6. .6 To turn on UJT, the forward bias on the emitter diode should be the peak point voltage. (A) Less than (B) More than (C) Equal to (D) None of the aboveShow All Answers 7. .7 A UJT is sometimes called (A) Low resistance diode (B) High resistance diode (C) Single-base diode (D) Double-based diodeShow All Answers 8. .8 Between the peak point and the valley point of UJT emitter characteristics we have (A) Saturation region (B) Cut-off region (C) Negative resistance region (D) None of the above regionShow All Answers 9. .9 Which of the following is not a characteristic of UJT? (A) Intrinsic standoff ratio (B) Negative resistance (C) Peak-point voltage (D) Bilateral conductionShow All Answers 10. .10 The UJT may be used as (A) A saw tooth generator (B) An amplifier (C) A rectifier (D) None of theseShow All Answers 11. .11 The device that exhibits negative resistance region is (A) Diac (B) Triac (C) UJT (D) TransistorShow All Answers 12. .12 In a phototransistor, base current is (A) Directly proportional to light (B) Set by a bias voltage (C) Inversely proportional to light (D) Not a factorShow All Answers 13. .13 Phototransistors are used in (A) Optocouplers (B) All of these (C) Optical fiber (D) Relay control circuitsShow All Answers 14. .14 The phototransistor effectively converts variations in light energy to (A) Digital signals (B) An electrical signal (C) Chemical energy (D) Mechanical energyShow All Answers 15. .15 LASCR, when activated by a sufficient amount of light, conducts current (A) In both directions (B) In one direction (C) In either one or both directions (D) Do not conductShow All Answers 16. .16 LASCR conducts by applying light of specific (A) Intensity (B) Frequency (C) Time (D) None of theseShow All Answers 17. .17 The key advantage of an optocoupler between the input and output circuits is the electrical (A) Connection (B) None of these (C) Both a & b (D) IsolationShow All Answers 18. .18 Which of the following is not a type of an Optocoupler (A) UJT (B) Photo-darlington (C) Photo-SCR (D) Photo-transistorShow All Answers 19. .19 An electronic component that interconnects two separate electrical circuits by means of a light sensitive optical interface (A) Triac (B) Optocoupler (C) SCR (D) DiacShow All Answers 20. .20 The optocouplers works well on high-voltage signals. (A) AC only (B) Either AC or DC (C) DC only (D) None of the aboveShow All Answers