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 worksheetPractise 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
+−3 VR1​ = 600 ΩR2​ = 150 ΩR3​ = 120 ΩR4​ = ?abG0

The Wheatstone bridge in the diagram is balanced: the galvanometer reads zero. R₁ = 600 Ω, R₂ = 150 Ω and R₃ = 120 Ω. Find the unknown resistor R4.

R1 = 600 ΩR2 = 150 ΩR3 = 120 Ω
R4 = Ω
2.Easy
+−5 VR1​ = 150 ΩR2​ = 150 ΩR3​ = 300 ΩR4​ = 1000 Ωab+−

The bridge shown is supplied with Vs = 5 V and its output is open. Find the current Is drawn from the supply, in mA.

Vs = 5 VR1 = 150 ΩR2 = 150 ΩR3 = 300 ΩR4 = 1000 Ω
Is = mA
3.Medium
+−9 V350 Ω350 Ω + ΔR350 Ω350 Ωab+−Vab​ = ?

A bridge has four 350 Ω arms and Vs = 9 V. The sensor R₂ increases by ΔR = 28 Ω. Find the exact output Vab in mV.

Vs = 9 VR = 350 ΩΔR = 28 Ω
Vab = mV
4.Medium
+−12 V120 Ω120 Ω + ΔR120 Ω120 Ωab+−Vab​ = ?

A bridge has four 120 Ω arms and Vs = 12 V. The sensor R₂ increases by ΔR = 18 Ω. Find the exact output Vab in mV.

Vs = 12 VR = 120 ΩΔR = 18 Ω
Vab = mV
5.Hard
+−3 V120 Ω − ΔR120 Ω + ΔR120 Ω120 Ωab+−Vo​ = ?

A bridge with 120 Ω arms is excited with 3 V and has two active gauges in adjacent arms, one in tension and one in compression (half bridge). The gauge factor is 2.05 and the strain is 600 µε. Find the bridge output Vo in mV.

Vs = 3 VGF = 2.05ε = 600 µε
Vo = mV
6.Hard
+−2.5 V1000 Ω − ΔR1000 Ω + ΔR1000 Ω1000 Ωab+−Vo​ = ?

A bridge with 1000 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 and the strain is 1000 µε. Find the bridge output Vo in mV.

Vs = 2.5 VGF = 2ε = 1000 µε
Vo = mV

Answer key

  1. 1. R4 = 30 Ω
  2. 2. Is = 20.51 mA
  3. 3. Vab = 173.1 mV
  4. 4. Vab = 418.6 mV
  5. 5. Vo = 1.845 mV
  6. 6. Vo = 2.5 mV

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