C bjt-biasing-and-stabilization
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The document discusses biasing and stabilization of BJT transistor circuits. It covers topics like dc and ac load lines, selecting the Q-point location for maximum output swing and minimal distortion, biasing circuits like potential divider biasing that provide stability and independence from transistor characteristics like beta. Improper biasing can lead to output distortion or device overheating. Components like resistors and diodes are used for bias compensation in transistor circuits.
C bjt-biasing-and-stabilization
- 1. (c) BJT BIASING AND STABILIZATION 1. The dc load line of transistor circuit (a) is a graph between IC and VCE (b) is a graph between IC and IB (c) does not contain the Q Point (d) is a curved line 2. The ac load line of a transistor circuit is steeper than its dc line because (a) ac signal sees less load resistance (b) IC is higher (c) input signal varies in magnitude (d) none of the above 3. The maximum peak to peak output voltage swing is obtained when Q point of a circuit is located (a) near saturation point (b) near cutoff point (c) at the center of the load line (d) atleast on the load line 4. The positive part of the output signal in a transistor circuit starts clipping, if Q point of the circuit moves (a) toward the saturation point (b) toward the cutoff point (c) toward the center of the load line (d) none of the above 5. The negative part of the output signal in a transistor circuit starts clipping if the Q point of the circuit moves (a) toward the saturation point (b) toward the cutoff point (c) toward the center of the load line (d) none of the above 6. The Q-point in a voltage amplifier is selected in the middle of the active region because (a) it gives better stability (b) the circuit needs a small (c) the biasing circuit then need less number of resistors (d) it gives distortions less output 7. The biasing circuit that gives best stability to Q point is (a) base resistance biasing (b) feedback resistor biasing
- 2. (c) potential divider biasing (d) emitter resistor biasing 8. The potential divider biasing is used in amplifiers to (a) limit the input ac signal going to the base (b) reduce dc base current (c) reduce the cost of the circuit by limiting the number of resistors (d) make the operating point almost independent of β 9. The ideal value of stability factor of a biasing circuit is (a) 1 (b) 5 (c) 10 (d) 100 10. The universal bias stabilization circuit is the most popular because (a) IC does not depend on transistor characteristic (b) its β sensitivity is low (c) voltage divider is heavily loaded by transistor base (d) IC equals to IE 11. Improper biasing of the transistor circuit leads to (a) excessive heat production at collector terminal (b) distortion in output signal (c) faulty location of load line (d) heavy loading of emitter terminal 12. The voltage divider biasing circuit is used in amplifiers quite often because it (a) limits the ac signal going to base (b) makes the operating point almost independent of β (c) reduces the dc base current (d) reduces the cost of the circuit 13. For a transistor amplifier with self- biasing network, the following components are used: R1 = 4KΩ, R2 = 4KΩ and RE = 1KΩ, the approximate value of stability factor will be (a) 4 (b) 3 (c) 2 (d) 1.5
- 3. 14. Which of the following components are used for bias compensation in transistor circuit (a) resistors (b) rectifier diodes (c) thermistors (d) both (b) and (c) above Answers 1. (a) 2. (a) 3. (c) 4. (b) 5. (a) 6. (d) 7. (c) 8. (d) 9. (a) 10. (b) 11. (b) 12. (b) 13. (b) 14. (d)