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 = 15 V and its output is open. Find the current I_s drawn from the supply, in mA.

V_s = 15 VR₁ = 800 ΩR₂ = 100 ΩR₃ = 500 ΩR₄ = 250 Ω

I_s = mA

2.Easy

In the bridge shown, V_s = 9 V, R₁ = 60 Ω and R₂ = 150 Ω. Find the voltage V_a of node a with respect to the negative supply rail.

V_s = 9 VR₁ = 60 ΩR₂ = 150 ΩR₃ = 800 ΩR₄ = 150 Ω

V_a = V

3.Medium

A 100 Ω strain gauge is one arm (R₂) of a bridge with four equal 100 Ω arms and an excitation of 3 V. Find the power P_g dissipated in the gauge, in mW. Self-heating limits the excitation.

V_s = 3 VR = 100 Ω

P_g = mW

4.Medium

A bridge has four 330 Ω arms and V_s = 10 V. The sensor R₂ increases by ΔR = 26.4 Ω. Find the exact output V_ab in mV.

V_s = 10 VR = 330 ΩΔR = 26.4 Ω

V_ab = mV

5.Hard

A bridge with 120 Ω arms is excited with 3 V and has one active gauge (quarter bridge). The gauge factor is 2 and the strain is 250 µε. Find the bridge output V_o in mV.

V_s = 3 VGF = 2ε = 250 µε

V_o = mV

6.Hard

A bridge with 350 Ω arms is excited with 5 V and has one active gauge (quarter bridge). The gauge factor is 2 and the strain is 1000 µε. Find the bridge output V_o in mV.

V_s = 5 VGF = 2ε = 1000 µε

V_o = mV

Answer key

1. I_s = 36.67 mA
2. V_a = 6.429 V
3. P_g = 22.5 mW
4. V_ab = 192.3 mV
5. V_o = 0.375 mV
6. V_o = 2.5 mV

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