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 = 20 ΩR₂ = 80 ΩR₃ = 50 ΩR₄ = 1000 Ω

I_s = mA

2.Easy

The Wheatstone bridge in the diagram is balanced by adjusting R₃. R₁ = 80 Ω, R₂ = 200 Ω and R₄ = 120 Ω. Find the setting R₃.

R₁ = 80 ΩR₂ = 200 ΩR₄ = 120 Ω

R₃ = Ω

3.Medium

A bridge has four 350 Ω arms and V_s = 9 V. The sensor R₂ increases by ΔR = 52.5 Ω. Find the exact output V_ab in mV.

V_s = 9 VR = 350 ΩΔR = 52.5 Ω

V_ab = mV

4.Medium

A bridge has four 200 Ω arms and V_s = 2 V. The sensor R₂ increases by ΔR = 50 Ω. Find the exact output V_ab in mV.

V_s = 2 VR = 200 ΩΔR = 50 Ω

V_ab = mV

5.Hard

A quarter bridge (one active gauge, GF = 2) is excited with 10 V. The largest strain to be measured is 750 µε, and it must give 2.5 V at the input of an analogue-to-digital converter. Find the amplifier gain G.

V_s = 10 VGF = 2ε_max = 750 µεV_FS = 2.5 V

G =

6.Hard

A bridge with 1000 Ω arms is excited with 10 V and has one active gauge (quarter 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. I_s = 131.4 mA
2. R₃ = 48 Ω
3. V_ab = 314 mV
4. V_ab = 111.1 mV
5. G = 666.7
6. V_o = 2 mV

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