Chapter 16 Self Test: Operational Amplifiers - Electronics Principles by Malvino/Bates

What usually controls the open-loop cutoff frequency of an op amp? a. Stray-wiring capacitance b. Base-emitter capacitance c. Collector-base capacitance d. Compensating capacitance

d

A compensating capacitor prevents a. Voltage gain b. Oscillations c. Input offset current d. Power bandwidth

b

At the unity-gain frequency, the open-loop voltage gain is a. 1 b. Av(mid) c. Zero d. Very large

a

The cutoff frequency of an op amp equals the unity-gain frequency divided by a. The cutoff frequency b. Closed-loop voltage gain c. Unity d. Common-mode voltage gain

b

If the cutoff frequency is 20 Hz and the midband open-loop voltage gain is 1,000,000, the unity-gain frequency is a. 20 Hz b. 1 MHz c. 2 MHz d. 20 MHz

d

If the unity-gain frequency is 5 MHz and the midband open-loop voltage gain is 100,000, the cutoff frequency is a. 50 Hz b. 1 MHz c. 1.5 MHz d. 15 MHz

a

The initial slope of a sine wave is directly proportional to a. Slew rate b. Frequency c. Voltage gain d. Capacitance

b

When the initial slope of a sine wave is greater than the slew rate, a. Distortion occurs b. Linear operation occurs c. Voltage gain is maximum d. The op amp works best

a

The power bandwidth increases when a. Frequency decreases b. Peak value decreases c. Initial slope decreases d. Voltage gain increases

b

A 741C contains a. Discrete resistors b. Inductors c. Active-load resistors d. A large coupling capacitor

c

A 741C cannot work without a. Discrete resistors b. Passive loading c. DC return paths on the two bases d. A small coupling capacitor

c

The input impedance of a BIFET op amp is a. Low b. Medium c. High d. Extremely high

d

An LF157A is a. Diff amp b. Source follower c. Bipolar op amp d. BIFET op amp

d

If the two supply voltages are ±12 V, the MPP value of an op amp is closest to a. 0 b. ±12 V c. ±2 V d. ±4 V

d

The open-loop cutoff frequency of a 741C is controlled by a. A coupling capacitor b. The output short-circuit current c. The power bandwidth d. A compensating capacitor

d

The 741C has a unity-gain frequency of a. 10 Hz b. 20 kHz c. 1 MHz d. 15 MHz

c

The unity-gain frequency equals the product of closed-loop voltage gain and the a. Compensating capacitance b. Tail current c. Closed-loop cutoff frequency d. Load resistance

c

If funity is 10 MHz and midband open-loop voltage gain is 200,000, then the open-loop cutoff frequency of the op amp is a. 10 Hz b. 20 Hz c. 50 Hz d. 100 Hz

c

The initial slope of a sine wave increases when a. Frequency decreases b. Peak value increases c. Cc increases d. Slew rate decreases

b

If the frequency of the input signal is greater than the power bandwidth, a. Slew-rate distortion occurs b. A normal output signal occurs c. Output offset voltage increases d. Distortion may occur

a

An op amp has an open base resistor. The output voltage will be a. Zero b. Slightly different from zero c. Maximum positive or negative d. An amplified sine wave

c

An op amp has a voltage gain of 200,000. If the output voltage is 1 V, the input voltage is a. 2 µV b. 5 µV c. 10 mV d. 1 V

b

A 741C has supply voltages of ±15 V. If the load resistance is large, the MPP value is approximately a. 0 b. ±15 V c. ±7 V d. ±30 V

c

Above the cutoff frequency, the voltage gain of a 741C decreases approximately a. 10 dB per decade b. 20 dB per octave c. 10 dB per octave d. 20 dB per decade

d

The voltage gain of an op amp is unity at the a. Cutoff frequency b. Unity-gain frequency c. Generator frequency d. Power bandwidth

b

When slew-rate distortion of a sine wave occurs, the output a. Is larger b. Appears triangular c. Is normal d. Has no offset

b

A 741C has a. A voltage gain of 100,000 b. An input impedance of 2 MΩ c. An output impedance of 75 Ω d. All of the above

d

The closed-loop voltage gain of an inverting amplifier equals a. The ratio of the input resistance to the feedback resistance b. The open-loop voltage gain c. The feedback resistance divided by the input resistance d. The input resistance

c

The noninverting amplifier has a a. Large closed-loop voltage gain b. Small open-loop voltage gain c. Large closed-loop input impedance d. Large closed-loop output impedance

c

The voltage follower has a a. Closed-loop voltage gain of unity b. Small open-loop voltage gain c. Closed-loop bandwidth of zero d. Large closed-loop output impedance

a

A summing amplifier can have a. No more than two input signals b. Two or more input signals c. A closed-loop input impedance of infinity d. A small open-loop voltage gain

b