Op-amp circuits worksheet with answers

Free printable Op-amp circuits worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
−+Vout​Rf​ = 47 kΩVin​ = −2 VR1​ = 22 kΩI1​

The op-amp is ideal and runs from ±15 V supplies. Find the current I1 through R₁, flowing towards the op-amp.

Vin = −2 VR1 = 22 kΩRf = 47 kΩ
I1 = mA
2.Easy
−+Vout​1.5 VRs​ = 47 kΩRL​1 kΩIL​

A sensor behaves like a 1.5 V source with an internal resistance Rs = 47 kΩ. It feeds a load RL = 1 kΩ through an ideal voltage follower (unity-gain buffer). Find the load current IL supplied by the op-amp output.

Vs = 1.5 VRs = 47 kΩRL = 1 kΩ
IL = mA
3.Medium
−+Vout​Rf​ = ?R1​ = 10 kΩVin​

Choose the feedback resistor Rf that gives this non-inverting amplifier a voltage gain of 51.

R1 = 10 kΩAv = 51
Rf = kΩ
4.Medium
−+Vout​R2​ = 4.7 kΩV1​ = 1.8 VR1​ = 2 kΩV2​ = 2 VR3​ = 2 kΩR4​ = 4.7 kΩ

The difference amplifier uses an ideal op-amp with ±15 V supplies, with R3 = R1 and R4 = R2. Find the output voltage Vout.

V1 = 1.8 VV2 = 2 VR1 = R3 = 2 kΩR2 = R4 = 4.7 kΩ
Vout = V
5.Hard
Vin​V1​Vout​stage 1: invertingR1​ = 2 kΩRf1​ = 22 kΩstage 2: non-invertingR2​ = 47 kΩRf2​ = 1 kΩ

Two ideal op-amp stages are connected in cascade: an inverting amplifier (R1, Rf1) followed by a non-inverting amplifier (R2 to ground, Rf2 in the feedback). Both run from ±15 V supplies. The input is Vin = −0.9 V. Find the output voltage Vout.

R1 = 2 kΩRf1 = 22 kΩR2 = 47 kΩRf2 = 1 kΩVin = −0.9 V
Vout = V
6.Hard
−+Vout​R2​ = 2 kΩV1​ = −1.4 VR1​ = 100 kΩV2​ = 1.2 VR3​ = 2 kΩR4​ = 100 kΩ

The op-amp is ideal and runs from ±15 V supplies. The resistor ratios are not matched. Find the output voltage Vout.

V1 = −1.4 VV2 = 1.2 VR1 = 100 kΩR2 = 2 kΩR3 = 2 kΩR4 = 100 kΩ
Vout = V

Answer key

  1. 1. I1 = −0.09091 mA
  2. 2. IL = 1.5 mA
  3. 3. Rf = 500 kΩ
  4. 4. Vout = 0.47 V
  5. 5. Vout = 10.11 V
  6. 6. Vout = 1.228 V

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