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
+−9 VR1​ = 600 ΩR2​ = 1000 ΩR3​ = ?R4​ = 60 ΩabG0

The Wheatstone bridge in the diagram is balanced by adjusting R₃. R₁ = 600 Ω, R₂ = 1000 Ω and R₄ = 60 Ω. Find the setting R3.

R1 = 600 ΩR2 = 1000 ΩR4 = 60 Ω
R3 = Ω
2.Easy
+−2 VR1​ = 60 ΩR2​ = 60 ΩR3​ = 10 ΩR4​ = 300 Ωab+−

The bridge shown is supplied with Vs = 2 V and its output is open. Find the current Is drawn from the supply, in mA.

Vs = 2 VR1 = 60 ΩR2 = 60 ΩR3 = 10 ΩR4 = 300 Ω
Is = mA
3.Medium
+−2 V220 Ω220 Ω + ΔR220 Ω220 Ωab+−Vab​ = ?

A bridge has four 220 Ω arms and Vs = 2 V. The sensor R₂ increases by ΔR = 17.6 Ω. Find the exact output Vab in mV.

Vs = 2 VR = 220 ΩΔR = 17.6 Ω
Vab = mV
4.Medium
+−6 V300 Ω300 Ω300 Ω300 Ωab+−

A 300 Ω strain gauge is one arm (R₂) of a bridge with four equal 300 Ω arms and an excitation of 6 V. Find the power Pg dissipated in the gauge, in mW. Self-heating limits the excitation.

Vs = 6 VR = 300 Ω
Pg = mW
5.Hard
+−2.5 V350 Ω350 Ω + ΔR350 Ω350 Ωab+−Vo​

A quarter bridge (one active gauge, GF = 2.05) is excited with 2.5 V. The largest strain to be measured is 750 µε, and it must give 5 V at the input of an analogue-to-digital converter. Find the amplifier gain G.

Vs = 2.5 VGF = 2.05εmax = 750 µεVFS = 5 V
G =
6.Hard
+−10 V120 Ω120 Ω + ΔR120 Ω120 Ωab+−Vo​

A quarter bridge (one active gauge, GF = 2.05) is excited with 10 V. The largest strain to be measured is 750 µε, and it must give 3.3 V at the input of an analogue-to-digital converter. Find the amplifier gain G.

Vs = 10 VGF = 2.05εmax = 750 µεVFS = 3.3 V
G =

Answer key

  1. 1. R3 = 36 Ω
  2. 2. Is = 23.12 mA
  3. 3. Vab = 38.46 mV
  4. 4. Pg = 30 mW
  5. 5. G = 5203
  6. 6. G = 858.5

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