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

The bridge shown is supplied with V_s = 12 V and its output is open. Find the current I_s drawn from the supply, in mA.

V_s = 12 VR₁ = 800 ΩR₂ = 60 ΩR₃ = 600 ΩR₄ = 150 Ω

I_s = mA

2.Easy

The bridge shown is supplied with V_s = 6 V and its output is open. Find the current I_s drawn from the supply, in mA.

V_s = 6 VR₁ = 50 ΩR₂ = 500 ΩR₃ = 1000 ΩR₄ = 1000 Ω

I_s = mA

3.Medium

A bridge has four 470 Ω arms and V_s = 12 V. The sensor R₂ increases by ΔR = 94 Ω. Find the exact output V_ab in mV.

V_s = 12 VR = 470 ΩΔR = 94 Ω

V_ab = mV

4.Medium

A bridge has four 150 Ω arms and V_s = 6 V. The sensor R₂ increases by ΔR = 0.75 Ω. Using the small-change approximation, find the output V_ab in mV.

V_s = 6 VR = 150 ΩΔR = 0.75 Ω

V_ab = mV

5.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 2.12 and the strain is 250 µε. Find the bridge output V_o in mV.

V_s = 10 VGF = 2.12ε = 250 µε

V_o = mV

6.Hard

A bridge with 120 Ω arms is excited with 2.5 V and has two active gauges in adjacent arms, one in tension and one in compression (half bridge). The gauge factor is 2.12 and the strain is 1000 µε. Find the bridge output V_o in mV.

V_s = 2.5 VGF = 2.12ε = 1000 µε

V_o = mV

Answer key

1. I_s = 29.95 mA
2. I_s = 13.91 mA
3. V_ab = 545.5 mV
4. V_ab = 7.5 mV
5. V_o = 5.3 mV
6. V_o = 2.65 mV

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