For nos. 1 6 For a certain CE amplifier with the following values: Vcc = +16Vdc, R1=90 kilo Ω, R2 = 10 kilo Ω, Cs = 10 uF, Rc = 2.2 kilo Ω, Re = 0.68 kilo Ω, Cc = 10 uF, NPN transistor with beta of 210 and ro = 50 kohm. 1. Determine the collector current a. 2.32 mA b. 3.22 mA c. 2.22 mA d. 1.32 mA 2. Determine the voltage between the voltage between the base and the collector (VBC) a. 11.488 b. -11.488 d. 14.811 d. -14.811 3. Determine the collector voltage a. 13.1 volts b. -13.1 volts c. 12.2 volts d. -12.2 volts 4. Determine the input impedance a. 4.5 kohm b. 5.5kohm c. 7.5 kohm d. 8.5 kohm 5. Determine the voltage gain of the circuit a. -1.31 b. -3.13 c. 3.13 d. 1.31 6. If a 10 uF capacitor is placed across the emitter resistor. Determine the voltage gain. a. 112 b. -112 c. -211 d. 211 –
For nos. 7-12 A CE arrangement in VDB configuration uses a PNP transistor having an amplification factor of 120 and ro = 50 kilo Ω. If it has the following values: Cs = 10 uF, R1 = 47 kohm, R2 = 10 kohm, Cc = 10 uF, Rc = 2.4 kohm, Re = 1.1 kohm, Ce = 10 uF, Vcc = -18 volts. 7. What is the emitter current? a. 2.24 mA b. -2.24 mA c. 3.42 mA d. -3.42 mA 8. What is the voltage between the collector and base (VBC)? a. 6.49 volts b. -4.96 volts c. 9.46 volts d. 4.96 volts 9. Determine the input impedance a. 4.2 kohm b. 3.2 kohm c. 2.2 kohm d. 1.2 kohm 10. If the network is connected to a 1500 Ω load. Determine the loaded voltage gain. a. -79.53 c. -112.53 d. -97.35 d. -121.35 11. If the network is connected to a 1500 Ω load and a 300 Ω source resistance. Determine the total voltage gain and current gain of the system. a. -63.624,21.71 -63.624,21.71 b. -36.42,7.212 c. -63.53,-12.71 d. -36.42,2.717 12. If the network is connected to a 1500 Ω load and the bypassed capacitor at the emitter resistor is removed. What is the loaded voltage gain of the circuit? a. -0.83 b. -12.54 c. -10.2 d. -2.35 For 13-18 An emitter follower configuration with that following values: Vcc = +12 Vdc, Rb = 220 kilo Ω, Cs = 10 uF, Re = 3.3 kilo Ω, Ce = 10 uF, NPN transistor with amplifi cation factor of 100 and ro = 100 kohms. 13. What is the emitter current? a. 20.42 uA b. 22.42 uA c. 2.06 mA d. 4.06 mA 14. What is the input impedance of the circuit? a. 133 kilo Ω b. 150 kilo Ω c. 52.34 kilo Ω d. 75.32 kilo Ω 15. What is the output impedance of the circuit? a. 2.5 kilo Ω b. 12.56 Ω c. 1.5 kilo Ω d. 20 Ω 16. Determine the current gain of the circuit a. 39.67 b. 93.67 c. 67.39 d. 79.93 17. Determine the voltage gain a. 1 b. 34.45 c. 10.18 d. 12.10 18. What is the output if the in put signal is 25 mV? a. 55 mV c. 75 mV c. 25 mV d. 45 mV For 19-25 For a CB configuration using the following values: PNP transistor with alpha = 0.98 and ro = 1megaohms, Re = 1 kiloohms, Cs = 10uF, VEE = -2V, Rc = 5kiloohms, Cc = 10 uF, VCC = -8V. 19. Determine the base current a. 26 uA b. 24 uA c. 22 uA d. 20 uA 20. Determine the voltage between the collector and emitter a. 10.2 V b. -10.2 V c. -2.2 V d. 2.2 V 21. Determine the input impedance a. 19.61 b. 2000 Ω c. 35.54 d. 1.2 kohm 22. Determine the output i mpedance
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a. 5 kilo Ω b. 3 kilo Ω c. 1 kilo Ω d. 500 Ω 23. What is the voltage gain of the circuit? a. 1 b. 12.45 c. 250 d. 2.56 24. What is the current gain of the circuit? a. 1 b. 12.45 c. 250 d. 2.56 25. If the circuit is connected to a 1000 ohms load and 300 Ω source resistance. What is the total system gain? a. 1 b. 12.45 c. 250 d. 2.56 For 26-30
26. Determine the emitter current at stage 1. a. 4.07 mA b. 3.07 mA c. 2.07 mA d. 1.07 mA 27. Determine VCE 2 a. 10.02 V b. 4.77 V c. 6.97 V d. 20 V 28. Determine the voltage gain of stage 2 a. -338.46 b. -150.38 c. -1 d. -20.32 29. Determine the overall voltage gain of the system a. 24145 b. 34900 c. 250 d. 530 30. If the two stage amplifier is connected to a 4700 Ω load. What is the total voltage gain of the system? a. 24145 b. 34900 c. 250 d. 530
For 31-33 A two stage cascaded amplifier that uses the following values for stage 1; CE VDB configuration, NPN transistor with amplification factor of 150 and ro = i nfinity, Cs = 10 uF, R1 = 24 kilo Ω, R2 = 6.2 kilo Ω, Cc = 10uF, Rc = 5.1 kilo Ω, Ce = 50 uF, Re = 1.5kiloohms. The first stage is capacitively coupled at the the base of the second stage that uses the following values: ; CE VDB configuration, NPN transistor with amplification factor of 150 and ro = infinity, Cs = 10 uF, R1 = 24 kilo Ω, R2 = 6.2 kilo Ω, Cc = 10uF, Rc = 5.1 kilo Ω, Ce = 50 uF, Re = 1.5kiloohms. If the whole system is connected with +15 volts supply. 31. Determine the voltage gain of the first and second each stage respectively. a. -80,-43.75 b. -80,-311 c. -50,-43.75 d. -311,-80 32. Determine the overall voltage gain the system a. 23600 b. 3500 c. -23600 d. -3500 33. If the network is connected to a 3000 Ω load. What is the output of the amplifier if it has a 25 uV signal? a. 87.5 mV b. -87.5 mV c. 218 mV d. -218 mV
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For 34-36
34. For the cascade system above, determine the voltage at the emitter of stage 1 a. 3.7 V b. 4.7 V c. 5.7 V 35. Determine re2 a. 10 Ω b. 7 Ω c. 3 Ω 36. Determine the overall voltage gain of the system a. -214 b. -142 c. -124
d. 6.7 V d. 1 Ω d. -421
For the darlington circuit shown,
37. Determine the emitter current. a. 20.44 mA b. 2.044 mA c. 4.022 mA 38. Determine the voltage between the collector and emitter a. 15.03 V b. 13.03 V c. 11.03 V 39. Determine the input impedance a. 1.6 Mohms b. 200 kilo Ω c. 2.54 Ω 40. Determine the output impedance a. 1.6 Mohms b. 200 kilo Ω c. 2.54 Ω 41. Determine the voltage and current gain a. 4100,10 b. 4100,1 c. 1400,1
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d. 40.22 mA d. 10.03 V d. 125.3 Ω d. 125.3 Ω d, 1400,10
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42. For the figure, determine the current mirrored (I) a. 10.65 mA b. 9.65 mA c. 8.65 mA
d. 7.65
mA
For nos. 43-45 A two stage amplifier system employs a transistor emitter follower configuration prior to common base configuration to ensure that maximum percentage of applied signal appears at the input of the common base. The following are the components of the system: Common Collector Common Base Zi = 10 kilo ohm Zi = 26 ohm Zo = 12 ohm Zo = 5100 ohm Av(no load) = 1 Av (no load) = 240 If a load of 8200 is applied and source resistance of 1000 ohm is connected
43. Find the loaded gain for each stage a. 0.68,148 b. 0.98,148 44. Find the total loaded current gain of the system a. 123.4 b. 132.3 45. Find Av(s) a. 3.70 b. 8.75
c.0.86,184
d. 0.89,194
c. 231.4
d.133.4 c. 15.2
d. 5.71
46. An NPN transistor in voltage divider bias configuration has a known R2=18 kilo ohm. Determine the necessary value of resistor and collector resistor to achieve quiescient level of Ic=2mA and Vce=10volts. When the circuit is supplied with +18 volts. a. 10 kilo ohm b. 5 kilo ohm c. 3 kilo ohm d. 1 kilo ohm 47. A CE arrangement using an NPN transistor has a base resistance of 100 kilo ohm and a collector resistance of 1 kilo ohm. Determine the value of beta of the transistor when a base current of 50 uA is applied and a voltage of 5 volts is dropped across the collector resistor. a. 50 b. 100 c. 150 d. 200 48. Determine the value of resistor to be placed at the base of a fixed bias circuit using a silicon transistor having beta value of 100, Vcc is 6 volts and DC bias of Vce = 5 volts and Ic =5mA. a. 150 kilo ohm b. 50 kilo ohm c. 135 kilo ohm d. 186 kilo ohm 49. A thyristor half wave controlled converter has a supply voltage of 240V at 50Hz and a load resistance of 1500 Ohm. When the firing delay angle is 30 the average value of load current is _________ a. 126 mA b. 67.2 mA c. 34.1 mA d. 118 mA 50. A 240V, 50Hz supply feeds a highly inductive load of 50 Ohm resistance through a half controlled thyristor bridge. When the firing angle α=45°, the l oad power is ____________ a. 418 W b. 512 W c. 367 W d. 128 W 51. The applied sine voltage to a SCR is VM=200V and R=10Ohm. If the gate trigger lags the ac supply by 120°, the average load current is a. 15/π A b. 5/π A c. -15/π A d. -5/π A
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