THOMAS FLOYD MCQ
Two FET amplifier are cascaded. The first stage has a voltage gain of 5 and the second stage has a voltage gain of 7. The overall voltage gain is A. 35 B. 12 C. dependent on the second stage loading
a
A CE amplifier is driving a 10 kΩ load. If RC = 2.2 kΩ and r'e = 10 Ω, the voltage gain is approximately A. 180 B. 220 C. 10 D. 1000
a
A CS amplifier has a load resistance of 10 kΩ and RD = 820 Ω, If gm = 5 mS and Vin = 500 mV, the output signal voltage is A. 1.89 V B. 2.05 V C. 25 V D. 0.5 V
a
A certain power supply filter produces an output with a ripple of 100 mV peak-to-peak and a dc value of 20 V. The ripple factor is A. 0.005 B. 0.05 C. 0.02 D. 0.00005
a
For a certain p-channel JFET, VGS(off) = 8 V. The value of VGS for an approximately midpoint bias is A. 2.34 V B. 0 V C. 4 V D. 1.25 V
a
For a common-collector amplifier, RE = 100 Ω, r'e = 10 Ω, and βAC = 150. The ac input resistance at the base is A. 16.5 Ω B. 15 kΩ C. 110 Ω D. 1500 Ω
a
If the feedback resistor in Question 17 is open, the voltage gain is A. increases B. decreases C. is not affected D. depends on Ri
a
If the output of a transistor amplifier is 5 V rms and the input is 100 mV rms, the voltage gain is A. 50 B. 500 C. 5 D. 100
a
The data sheet for a particular zener gives VZ = 10 V at IZT = 500 mA. ZZ for these conditions is A. 20 Ω B. 50 Ω C. 10 Ω D. unknown
a
When the rms output voltage of a bridge full wave rectifier is 20 V, the peak inverse voltage across the diodes is (neglecting the diode drop) A. 28.3 V B. 20 V C. 40 V D. 56.6 V
a
A 60 V peak full-wave rectified voltage is applied to a capacitor-input filter. If f = 120 Hz. RL = 10 k Ω and C = 10 μF, the ripple voltage is A. 0.6 V B. 5.0 V C. 6 mV D. 2.88 V
b
A certain class A power amplifier delivers 5 W to a load with an input signal power of 100 mW. The power gain is A. 100 B. 50 C. 250 D. 5
b
A certain class A power amplifier has VCEQ = 12 V and ICQ = 1 A. The maximum signal power output is A. 6 W B. 12 W C. 1 W D. 0.707 W
b
A certain common-drain (CD) amplifier with RS = 1.0 kΩ has a transconductance of 6000 μS. The voltage gain is A. 1 B. 0.86 C. 0.98 D. 6
b
A certain op-amp has a bias current of 50μA and 49.3μA. The input offset current is A. 700 nA B. 99.3μA C. 49.7μA D. none of these
b
For a certain JFET, IGSS = 10 nA at VGS = 10 V. The input resistance is A. 1 MΩ B. 1000 MΩ C. 100 MΩ D. 1000 mΩ
b
For a common-emitter amplifier, RC = 1.0 kΩ, RE = 390 Ω, and βac = 75. Assuming the RE is completely bypassed at the operating frequency, the voltage gain is A. 2.56 B. 66.7 C. 2.47 D. 75
b
For the circuit in Question 3, the diode must be able to withstand a reverse voltage of A. 5 V B. 10 V C. 20 V D. 3.18 V
b
If a 10 mV signal is applied to the base of the emitter-follower circuit in Question 5, the output signal is approximately A. 1.5 mV B. 10 mV C. 100 mV D. 150 mV
b
If the fr of the transistor used in a certain amplifier is 75 MHz and the bandwidth is 10 MHz, the voltage gain must be A. 750 B. 7.5 C. 10 D. 1
b
In a certain common-source (CS) amplifier, VDS = 3.2 V rms and VGS = 280 mV rms. The voltage gain is A. 1 B. 11.4 C. 8.75 D. 3.2
b
In a certain voltage-divider biased npn transistor, VB is 2.95 V. The dc emitter voltage is approximately A. 2.95 V B. 2.25 V C. 0.7 V D. 3.65 V
b
In the circuit of Question 7, if the frequency is reduced to the point where XC(bypass) = RE, the voltage gain A. remains the same B. is less C. is greater
b
The output of a certain two-supply class B push pull amplifier has a VCC of 20 V. If the load resistance is 50 Ω, the value of IC(sat) is A. 5 mA B. 0.4 A C. 4 mA D. 40 mA
b
The peak value of the input to a half-wave rectifier is 10 V. The approximate peak value of the output is A. 10.7 V B. 9.3 V C. 10 V D. 3.18 V
b
A certain inverting amplifier has a closed-loop gain of 25. The op-amp has an open-loop gain of 100,000. if another op-amp with an open loop gain of 200,000 is substituted in the configuration, the closed-loop gain A. doubles B. drops to 12.5 C. remains at 25 D. increases slightly
c
A certain inverting amplifier has an Ri of 0.1 kΩ and an Rf of 100 kΩ. The closed loop gain is A. 100,000 B. 1000 C. 101 D. 100
c
An amplifier has the following critical frequencies: 1.2 kHz, 950 Hz, 8 kHz, and 8.5 kHz. The bandwidth is A. 7550 Hz B. 7300 Hz C. 6800 Hz D. 7050 Hz
c
At the upper critical frequency, the peak output voltage of a certain amplifier is 10 V. The peak voltage in the midrange of the amplifier is A. 7.07 V B. 6.37 V C. 14.14 V D. 10 V
c
For a certain 12 V zener diode, a 10 mA change in zener current produces a 0.1 V change in zener voltage. The zener impedance for this current ranges is A. 0.1 Ω B. 100 Ω C. 10 Ω D. 1 Ω
c
If a certain op-amp has a midrange open-loop gain of 200,000 and a unity gain frequency of 5 MHz, the gain-bandwidth product is A. 200,000 Hz B. 1 x 1012 Hz C. 5,000,000 Hz D. not determinable from the information
c
If the load resistance in Question 7 is removed, the output voltage will A. stay the same B. decrease C. increase D. be zero
c
In a certain CS amplifier, RD = 1.0 kΩ, RS = 560 Ω, VDD = 10 V, and gm = 4500 μS. If the source resistor is completely bypassed, the voltage gain is A. 450 B. 45 C. 4.5 D. 2.52
c
In a common-emitter amplifier with voltage-divider bias, Rin(base) = 68 kΩ, R1 = 33 kΩ, and R2 = 15 kΩ. The total input resistance is A. 22.2 kΩ B. 68 kΩ C. 8.95 kΩ D. 12.3 kΩ
c
In an emitter bias circuit, RE = 2.7 k Ω and VEE = 15 V. The emitter current A. is 180 mA B. is 2.7 mA C. is 5.3 mA D. cannot be determined
c
The output of a particular op-amp increases 8 V in 12 μs. The slew rate is A. 96 V/μs B. 0.67 V/ μs C. 1.5 V/μs D. none of the above
c
The overall gain found in Question 14 can be expressed in decibels as A. 47.0 dB B. 35.6 dB C. 94.1 dB D. 69.8 dB
c
When the peak output voltage is 100 V, the PIV for each diode in a center-tapped full-wave rectifier is (neglecting the diode drop) A. 100 V B. 141 V C. 200 V D. 50 V
c
A silicon diode is in series with 1.0 kΩ resistor and a 5 V battery. If the anode is connected to the positive battery terminal, the cathode voltage with respect to the negative battery terminal is A. 0.7 V B. 5.7 V C. 0.3 V D. 4.3 V
d
If Av(d) = 3500 and Acm = 0.35, the CMRR is A. 1225 B. 10,000 C. 80 dB D. answers b and c
d
If a certain op-amp has a closed-loop gain of 20 and an upper critical frequency of 10 MHz, the gain-bandwidth product is A. 200 MHz B. 10 MHz C. the unity-gain frequency D. answer a and c
d
If the dc emitter current in a certain transistor amplifier is 3 mA, the approximate value of r'e is A. 3 Ω B. 3 kΩ C. 0.33 kΩ D. 8.33 Ω
d
If the input voltage to a voltage tripler has an rms value of 12 V, the dc output voltage is approximately A. 36 V B. 33.9 V C. 32.4 V D. 50.9 V
d
In a certain FET circuit, VGS = 0 V, VDD = 15 V, IDSS = 15 mA, and RD = 470 Ω. If RD is decreased to 330 Ω, IDSS is A. 1 mA B. 10.5 mA C. 19.5 mA D. 15 mA
d
In a certain oscillator, AV = 50. The attenuation of the feedback circuit must be A. 1 B. 0.01 C. 10 D. 0.02
d
In a darlington pair configuration, each transistor has an ac beta of 125. If RE is 560 Ω, the input resistance is A. 560 Ω B. 70 Ω C. 140 kΩ D. 8.75 MΩ
d
In the midrange of an amplifier's bandwidth, the peak output voltage is 6 V. At the lower critical frequency, the peak output voltage is A. 3 V B. 3.82 V C. 8.48 V D. 4.24 V
d
The average value of a full-wave rectified voltage with a peak value of 75 V is A. 37.5 V B. 23.9 V C. 53 V D. 47.8 V
d
The average value of a half-wave rectified voltage with a peak value of 200 V is A. 127.3 V B. 141 V C. 0 V D. 63.7 V
d
The data sheet for the transistor used in a CD amplifier specifies IGSS = 5 nA at VGS = 10 V. If the resistor from ate to ground, RG, is 50 MΩ, the total input resistance is approximately. A. 50 MΩ B. 200 MΩ C. 40 MΩ D. 20.5 MΩ
d
The gain of a certain amplifier decrease by 6 dB when the frequency is reduced from 1 kHz to 10 Hz. The roll-off is A. - 3 dB/decade B. - 6 dB/decade C. - 3 dB/octave D. - 6 dB/octave
d
The gain of a particular amplifier at a given frequency decreases by 6 dB when the frequency is doubled. The roll-off is A. - 12 dB/decade B. - 20 dB/decade C. - 6 dB/octave D. answer b and c
d