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
+−6 VR1​ = 400 ΩR2​ = 60 ΩR3​ = 80 ΩR4​ = 800 Ωab+−

In the bridge shown, Vs = 6 V, R₁ = 400 Ω and R₂ = 60 Ω. Find the voltage Va of node a with respect to the negative supply rail.

Vs = 6 VR1 = 400 ΩR2 = 60 ΩR3 = 80 ΩR4 = 800 Ω
Va = V
2.Easy
+−6 VR1​ = 10 ΩR2​ = 300 ΩR3​ = 50 ΩR4​ = ?abG0

The Wheatstone bridge in the diagram is balanced: the galvanometer reads zero. R₁ = 10 Ω, R₂ = 300 Ω and R₃ = 50 Ω. Find the unknown resistor R4.

R1 = 10 ΩR2 = 300 ΩR3 = 50 Ω
R4 = Ω
3.Medium
+−2 V300 Ω300 Ω + ΔR300 Ω300 Ωab+−Vab​ = ?

A bridge has four 300 Ω arms and Vs = 2 V. The sensor R₂ increases by ΔR = 24 Ω. Find the exact output Vab in mV.

Vs = 2 VR = 300 ΩΔR = 24 Ω
Vab = mV
4.Medium
+−3 V250 Ω250 Ω250 Ω250 Ωab+−

A 250 Ω strain gauge is one arm (R₂) of a bridge with four equal 250 Ω arms and an excitation of 3 V. Find the power Pg dissipated in the gauge, in mW. Self-heating limits the excitation.

Vs = 3 VR = 250 Ω
Pg = mW
5.Hard
+−2.5 V350 Ω350 Ω + ΔR350 Ω350 Ωab+−0.525 mV

A quarter bridge with one active gauge (GF = 2.1) is excited with 2.5 V. Under load the output reads 0.525 mV. Find the strain ε in µε.

Vs = 2.5 VGF = 2.1Vo = 0.525 mV
ε = µε
6.Hard
+−2.5 V120 Ω − ΔR120 Ω + ΔR120 Ω + ΔR120 Ω − ΔRab+−Vo​ = ?

A bridge with 120 Ω arms is excited with 2.5 V and has four active gauges, two in tension and two in compression (full bridge). The gauge factor is 2 and the strain is 1500 µε. Find the bridge output Vo in mV.

Vs = 2.5 VGF = 2ε = 1500 µε
Vo = mV

Answer key

  1. 1. Va = 0.7826 V
  2. 2. R4 = 1500 Ω
  3. 3. Vab = 38.46 mV
  4. 4. Pg = 9 mW
  5. 5. ε = 400 µε
  6. 6. Vo = 7.5 mV

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