EE 210 Exam 2 - Practice Questions and Answers | 2026 Revised Update | 10% Correct - PSU.

EE 210 Exam 2 - Practice Questions and Answers
|
2026 Revised Update | 10% Correct - PSU.


Op-Amp Circuits
1. In an ideal op-amp operating in the linear region, which statement is true?

 A) Input impedance is zero, output impedance is infinite
 B) Input impedance is infinite, output impedance is zero
 C) Input and output impedance are both infinite
 D) Input and output impedance are both zero

Correct Answer: B - Ideal op-amps have infinite input impedance (no current flows into
inputs) and zero output impedance (acts as ideal voltage source) .




2. For an op-amp in negative feedback, the voltage at the inverting input is:

 A) Always equal to the supply voltage
 B) Equal to the voltage at the non-inverting input
 C) Equal to the output voltage divided by the gain
 D) Always zero

Correct Answer: B - The virtual short concept states that in negative feedback, the
differential input voltage is driven to zero, so V⁻ = V⁺ .




3. What is the gain of a non-inverting op-amp configuration with R_f = 10kΩ and
R_1 = 1kΩ?

 A) 1
 B) 10
 C) 11

, D) 100

Correct Answer: C - Gain = 1 + (R_f/R_1) = 1 + (10k/1k) = 11 .




4. What is the gain of an inverting op-amp configuration with R_f = 20kΩ and R_in
= 10kΩ?

 A) -2
 B) 2
 C) 3
 D) -3

Correct Answer: A - Gain = -(R_f/R_in) = -(20k/10k) = -2 .




5. In the inverting op-amp configuration, the input resistance is:

 A) Equal to R_f
 B) Equal to R_in
 C) Infinite
 D) Zero

Correct Answer: B - Due to the virtual ground at the inverting input, the input
resistance equals R_in .




6. For the circuit below with Vi = 3 volts, what is Vo? (Standard inverting amplifier
with R_f = 20k, R_in = 10k)

Circuit description: Inverting op-amp configuration with R_in = 10kΩ, R_f = 20kΩ, Vi
applied to R_in

 A) 3V
 B) 6V
 C) -6V

,  D) 9V

Correct Answer: C - Vo = -(20k/10k)(3) = -6V .




7. A voltage follower (buffer) has a gain of:

 A) 0
 B) -1
 C) 1
 D) Infinite

Correct Answer: C - A voltage follower has unity gain (Vo = Vi) .




8. The output voltage of an op-amp is limited by:

 A) The input signal amplitude
 B) The power supply voltages
 C) The feedback resistor value
 D) The input impedance

Correct Answer: B - Op-amp output is limited by the supply rails (saturation) .




9. For the op-amp circuit shown, if Vi = 0.4V, will the output be positive or
negative? (Assuming inverting configuration)

 A) Positive
 B) Negative
 C) Zero
 D) Cannot be determined

Correct Answer: B - Inverting configuration produces output opposite in sign to input .