Question 1

Figure 3
-Refer to Figure 3. The value of dc bias current in R1 is

Accepted Answer

A)  43 mA
B)  90 mA
C)  86 mA
D)  48 mA A

Question 2

Figure 4
-Refer to Figure 4. The amplifier represented is

Accepted Answer

A)  class- C
B)  class- A
C)  class- B C

Question 3

The amplifier type that frequently has a resonant circuit load is

Accepted Answer

A)  class- AB
B)  class- C
C)  class- B
D)  class- A B

Question 4

Figure 5
-Refer to Figure 5. The center tap on the output transformer (markedA)should be connected to

Accepted Answer

A)  -VCC
B)  ground
C)  +VCC 
D)  nothing, it is left open

Question 5

Figure 3
-Refer to Figure 3. Note the input is a 5 Vrms sine wave. The ac power in RL is ideally

Accepted Answer

A)  1.56 W
B)  3.12 W
C)  0.31 W
D)  0.62 W

Question 6

The ratio of Pout to PDC is the efficiency of an amplifier.

Accepted Answer

A) True 
 B)False

Question 7

The maximum ideal efficiency for a class- A amplifier is

Accepted Answer

A)  80%
B)  40%
C)  55%
D)  25%

Question 8

Figure 6
-Refer to Figure 6. The combination of R1, C1, and the base- emitter diode form a

Accepted Answer

A)  positive clipping circuit
B)  clamping circuit
C)  negative clipping circuit
D)  coupling circuit

Question 9

Assume the Q point on a class- A amplifier is centered on the ac load line. The maximum peak- to- peak output voltage is

Accepted Answer

A)  1/2 VCEQ
B)  2 VCEQ
C)  1/2 VCC
D)  VCEQ

Question 10

A heat sink is used to

Accepted Answer

A)  prevent excessive current
B)  reduce the junction temperature
C)  reduce ambient temperature
D)  all of the above

Question 11

A class- B amplifier with Darlington transistors can use larger bias resistors.

Accepted Answer

A) True 
 B)False

Question 12

Figure 5
-Refer to Figure 5. The diode

Accepted Answer

A)  produces class- AB operation
B)  compensates for the base- emitter drops of the transistors
C)  helps prevent crossover distortion
D)  all of the above

Question 13

Figure 7
-Refer to Figure 7. The expected ac emitter voltage for Q1 is

Accepted Answer

A)  4.0 Vrms
B)  2.0 Vrms
C)  0 V
D)  none of the above

Question 14

Figure 1
-Refer to Figure 1. The voltage gain, Av, to the load is approximately

Accepted Answer

A)  11
B)  7.5
C)  5.4
D)  2.0

Question 15

Figure 6
-The transistor in a Class- C amplifier is biased for conduction for

Accepted Answer

A)  360°
B)  90°
C)  180°
D)  much less than 90°

Question 16

Figure 2 This is modification of Figure 1 (added QS1U1B12S1U1B0, QS1U1B13S1U1B0, and RS1U1B1LS1U1B0, deletion of CS1U1B13 S1U1B0and a changed value of RS1U1B1E1S1U1B0).
-Refer to Figure 2. If Vin = 1 Vrms, the ac power in RL is approximately

Accepted Answer

A)  2.6 W
B)  4.0 W
C)  680 mW
D)  1.3 W

Question 17

A class- A amplifier has an input resistance of 520 ▲ and a load resistance of 26 ▲. Assume a 1 Vrms input produces a 5 Vrms output The power gain is

Accepted Answer

A)  5
B)  100
C)  50
D)  500

Question 18

A class- A amplifier the quiescent power is dissipated only when a signal is present.

Accepted Answer

A) True 
 B)False

Question 19

Figure 2 This is modification of Figure 1 (added QS1U1B12S1U1B0, QS1U1B13S1U1B0, and RS1U1B1LS1U1B0, deletion of CS1U1B13 S1U1B0and a changed value of RS1U1B1E1S1U1B0).
-Refer to Figure 2. With no applied signal, the dc power dissipated in the load is approximately

Accepted Answer

A)  1.1 W
B)  0
C)  5.5 W
D)  2.8 W

Question 20

Figure 3
-Refer to Figure 3. This type of bias is called

Accepted Answer

A)  current- mirror biasing
B)  push- pull bias
C)  diode biasing
D)  mid- point bias

Exam 7: BJT Power Amplifiers

Figure 3 -Refer to Figure 3. The value of dc bias current in R1 is

Figure 4 -Refer to Figure 4. The amplifier represented is

The amplifier type that frequently has a resonant circuit load is

Figure 5 -Refer to Figure 5. The center tap on the output transformer (markedA) should be connected to

Figure 3 -Refer to Figure 3. Note the input is a 5 Vrms sine wave. The ac power in RL is ideally

The ratio of Pout to PDC is the efficiency of an amplifier.

The maximum ideal efficiency for a class- A amplifier is

Figure 6 -Refer to Figure 6. The combination of R1, C1, and the base- emitter diode form a

Assume the Q point on a class- A amplifier is centered on the ac load line. The maximum peak- to- peak output voltage is

A heat sink is used to

A class- B amplifier with Darlington transistors can use larger bias resistors.

Figure 5 -Refer to Figure 5. The diode

Figure 7 -Refer to Figure 7. The expected ac emitter voltage for Q1 is

Figure 1 -Refer to Figure 1. The voltage gain, Av, to the load is approximately

Figure 6 -The transistor in a Class- C amplifier is biased for conduction for

Figure 2 This is modification of Figure 1 (added Q₂, Q₃, and R_L, deletion of C₃and a changed value of R_E1) . -Refer to Figure 2. If Vin = 1 Vrms, the ac power in RL is approximately

A class- A amplifier has an input resistance of 520 ▲ and a load resistance of 26 ▲. Assume a 1 Vrms input produces a 5 Vrms output The power gain is

A class- A amplifier the quiescent power is dissipated only when a signal is present.

Figure 2 This is modification of Figure 1 (added Q₂, Q₃, and R_L, deletion of C₃and a changed value of R_E1) . -Refer to Figure 2. With no applied signal, the dc power dissipated in the load is approximately

Figure 3 -Refer to Figure 3. This type of bias is called

Exam 7: BJT Power Amplifiers

Figure 3 -Refer to Figure 3. The value of dc bias current in R1 is

Figure 4 -Refer to Figure 4. The amplifier represented is

The amplifier type that frequently has a resonant circuit load is

Figure 5 -Refer to Figure 5. The center tap on the output transformer (markedA) should be connected to

Figure 3 -Refer to Figure 3. Note the input is a 5 Vrms sine wave. The ac power in RL is ideally

The ratio of Pout to PDC is the efficiency of an amplifier.

The maximum ideal efficiency for a class- A amplifier is

Figure 6 -Refer to Figure 6. The combination of R1, C1, and the base- emitter diode form a

Assume the Q point on a class- A amplifier is centered on the ac load line. The maximum peak- to- peak output voltage is

A heat sink is used to

A class- B amplifier with Darlington transistors can use larger bias resistors.

Figure 5 -Refer to Figure 5. The diode

Figure 7 -Refer to Figure 7. The expected ac emitter voltage for Q1 is

Figure 1 -Refer to Figure 1. The voltage gain, Av, to the load is approximately

Figure 6 -The transistor in a Class- C amplifier is biased for conduction for

Figure 2 This is modification of Figure 1 (added Q2, Q3, and RL, deletion of C3 and a changed value of RE1) . -Refer to Figure 2. If Vin = 1 Vrms, the ac power in RL is approximately

A class- A amplifier has an input resistance of 520 ▲ and a load resistance of 26 ▲. Assume a 1 Vrms input produces a 5 Vrms output The power gain is

A class- A amplifier the quiescent power is dissipated only when a signal is present.

Figure 2 This is modification of Figure 1 (added Q2, Q3, and RL, deletion of C3 and a changed value of RE1) . -Refer to Figure 2. With no applied signal, the dc power dissipated in the load is approximately

Figure 3 -Refer to Figure 3. This type of bias is called

Figure 2 This is modification of Figure 1 (added Q₂, Q₃, and R_L, deletion of C₃and a changed value of R_E1) . -Refer to Figure 2. If Vin = 1 Vrms, the ac power in RL is approximately

Figure 2 This is modification of Figure 1 (added Q₂, Q₃, and R_L, deletion of C₃and a changed value of R_E1) . -Refer to Figure 2. With no applied signal, the dc power dissipated in the load is approximately