Wheatstone bridge & strain gauges worksheet with answers

Free printable Wheatstone bridge & strain gauges worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheet Practise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________ Date: ____________

1.Easy

Find the open-circuit output voltage V_ab = V_a − V_b of the bridge shown, with V_s = 3 V.

V_s = 3 VR₁ = 1000 ΩR₂ = 250 ΩR₃ = 500 ΩR₄ = 1000 Ω

V_ab = V

2.Easy

Find the open-circuit output voltage V_ab = V_a − V_b of the bridge shown, with V_s = 12 V.

V_s = 12 VR₁ = 500 ΩR₂ = 200 ΩR₃ = 600 ΩR₄ = 10 Ω

V_ab = V

3.Medium

Find the Thévenin resistance R_th of the bridge shown, seen from the output terminals a and b.

V_s = 12 VR₁ = 10 ΩR₂ = 300 ΩR₃ = 60 ΩR₄ = 500 Ω

R_th = Ω

4.Medium

A galvanometer with a resistance of 20 Ω is connected between a and b of the bridge shown (V_s = 12 V). Find the galvanometer current I_g from a to b, in µA.

V_s = 12 VR₁ = 100 ΩR₂ = 1000 ΩR₃ = 800 ΩR₄ = 1000 ΩR_g = 20 Ω

I_g = µA

5.Hard

A load cell (a full bridge of strain gauges) has a rated output of 2 mV/V at its rated load of 200 kg. It is excited with 10 V. Find its output V_o under a load of 40 kg.

2 mV/VF_rated = 200 kgV_s = 10 VF = 40 kg

V_o = mV

6.Hard

A bridge with 120 Ω arms is excited with 10 V and has four active gauges, two in tension and two in compression (full bridge). The gauge factor is 2 and the strain is 400 µε. Find the bridge output V_o in mV.

V_s = 10 VGF = 2ε = 400 µε

V_o = mV

Answer key

1. V_ab = −1.4 V
2. V_ab = 3.232 V
3. R_th = 63.25 Ω
4. I_g = 7639 µA
5. V_o = 4 mV
6. V_o = 8 mV

Full step-by-step solutions: practise this topic on examproblems.com.