elecs 2 (with ans)

5/20/2018 Elecs 2 (With Ans)

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1 |B J T A C A N D D C A N A L Y S I S M M L E

For nos. 1 6For a certain CE amplifier with the following values:Vcc = +16Vdc, R1=90 kilo , R2 = 10 kilo , Cs = 10 uF, Rc = 2.2 kilo , Re = 0.68 kilo , Cc = 10 uF, Ntransistor with beta of 210 and ro = 50 kohm.

1.

Determine the collector currenta. 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 voltagea. 13.1 volts b. -13.1 volts c. 12.2 volts d. -12.2 volt

4.

Determine the input impedancea.

4.5 kohm b. 5.5kohm c. 7.5 kohm d. 8.5 kohm5. Determine the voltage gain of the circuit

a.

-1.31 b. -3.13 c. 3.13 d. 1.316. 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. 7-12A CE arrangement in VDB configuration uses a PNP transistor having an amplification factor of 120 and ro = 50 kiloIf it has the following values: Cs = 10 uF, R1 = 47 kohm, R2 = 10 kohm, Cc = 10 uF, Rc = 2.4 kohm, Re = 1.1 koCe = 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 volts9. Determine the input impedance

a.

4.2 kohm b. 3.2 kohm c. 2.2 kohm d. 1.2 kohm10.If the network is connected to a 1500 load. Determine the loaded voltage gain.

a.

-79.53 c. -112.53 d. -97.35 d. -121.3511.If the network is connected to a 1500 load and a 300 source resistance. Determine the total voltage g

and current gain of the system.

a. -63.624,21.71 b. -36.42,7.212 c. -63.53,-12.71 d. -36.42,2.12.

If the network is connected to a 1500 load and the bypassed capacitor at the emitter resistor is removWhat is the loaded voltage gain of the circuit?

a.

-0.83 b. -12.54 c. -10.2 d. -2.35

For 13-18An emitter follower configuration with that following values: Vcc = +12 Vdc, Rb = 220 kilo , Cs = 10 uF, Re =

kilo , Ce = 10 uF, NPN transistor with amplification 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 mA14.

What is the input impedance of the circuit?a. 133 kilo b. 150 kilo c. 52.34 kilo d. 75.32 kilo

15.

What is the output impedance of the circuit?

a. 2.5 kilo b. 12.56 c. 1.5 kilo d. 20 16.

Determine the current gain of the circuita. 39.67 b. 93.67 c. 67.39 d. 79.93

17.

Determine the voltage gaina. 1 b. 34.45 c. 10.18 d. 12.10

18.

What is the output if the input signal is 25 mV?a. 55 mV c. 75 mV c. 25 mV d. 45 mV

For 19-25For 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,= 10 uF, VCC = -8V.

19.Determine the base currenta. 26 uA b. 24 uA c. 22 uA d. 20 uA

20.

Determine the voltage between the collector and emittera. 10.2 V b. -10.2 V c. -2.2 V d. 2.2 V

21.

Determine the input impedancea. 19.61 b. 2000 c. 35.54 d. 1.2 kohm

22.

Determine the output impedance


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a.

5 kilo b. 3 kilo c. 1 kilo d. 500 23.What is the voltage gain of the circuit?

a.

1 b. 12.45 c. 250 d. 2.5624.What is the current gain of the circuit?

a.

1 b. 12.45 c. 250 d. 2.5625.If the circuit is connected to a 1000 ohms load and 300 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 2a.

10.02 V b. 4.77 V c. 6.97 V d. 20 V28.Determine the voltage gain of stage 2

a.

-338.46 b. -150.38 c. -1 d. -20.3229.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 load. What is the total voltage gain of the system?a. 24145 b. 34900 c. 250 d. 530

For 31-33A two stage cascaded amplifier that uses the following values for stage 1; CE VDB configuration, NPN transistor w

amplification factor of 150 and ro = infinity, Cs = 10 uF, R1 = 24 kilo , R2 = 6.2 kilo , Cc = 10uF, Rc = 5.1 kiloCe = 50 uF, Re = 1.5kiloohms. The first stage is capacitively coupled at the the base of the second stage that uthe following values: ; CE VDB configuration, NPN transistor with amplification factor of 150 and ro = infinity, Cs =uF, R1 = 24 kilo , R2 = 6.2 kilo , Cc = 10uF, Rc = 5.1 kilo , Ce = 50 uF, Re = 1.5kiloohms. If the whole systis 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 systema.

23600 b. 3500 c. -23600 d. -3500

33.

If the network is connected to a 3000 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 1a.

3.7 V b. 4.7 V c. 5.7 V d. 6.7 V

35.

Determine re2a.

10 b. 7 c. 3 d. 1 36.Determine the overall voltage gain of the system

a.

-214 b. -142 c. -124 d. -421

For the darlington circuit shown,

37.

Determine the emitter current.

a.

20.44 mA b. 2.044 mA c. 4.022 mA d. 40.22 mA38.

Determine the voltage between the collector and emittera. 15.03 V b. 13.03 V c. 11.03 V d. 10.03 V

39.

Determine the input impedance

a. 1.6 Mohms b. 200 kilo c. 2.54 d. 125.3 40.

Determine the output impedancea. 1.6 Mohms b. 200 kilo c. 2.54 d. 125.3

41.Determine the voltage and current gaina. 4100,10 b. 4100,1 c. 1400,1 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 baconfiguration to ensure that maximum percentage of applied signal appears at the input of the comm

base. The following are the components of the system:Common Collector Common Base

Zi = 10 kilo ohm Zi = 26 ohmZo = 12 ohm Zo = 5100 ohmAv(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 stagea. 0.68,148 b. 0.98,148 c.0.86,184 d. 0.89,194

44. Find the total loaded current gain of the systema. 123.4 b. 132.3 c. 231.4 d.133.4

45. Find Av(s)a. 3.70 b. 8.75 c. 15.2 d. 5.71

46. An NPN transistor in voltage divider bias configuration has a known R2=18 kilo ohm. Determine

necessary value of resistor and collector resistor to achieve quiescient level of Ic=2mA and Vce=10voWhen 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 collec

resistance of 1 kilo ohm. Determine the value of beta of the transistor when a base current of 50 uAapplied 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 transishaving 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 1500Ohm. 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 bridWhen the firing angle =45, the load 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, thaverage load current is

a. 15/ A b. 5/ A c. -15/ A d. -5/ A

elecs 2 (with ans)

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