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A strain gauge forms one arm of the bridge shown in the figure below and has a nominal resistance without any load as RS = 300Ω. Other bridge resistances are R1 = R2 = R3 = 300Ω. The maximum permissible current through the strain gauge is 20 mA. During certain measurement when the bridge is excited by maximum per missible voltage and the strain gauge resistance is increased by 1% over the nominal value, the output voltage V0 in mV is
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- 56.02
- 40.83
- 29.85
- 10.02
Correct Option: C
Maximum permissible voltage
= (300 + 300) × 20 × 10–3 = 12V 
when Rs is increased by 1% new value of
R'e = 303 Ω
v0 = v0 – v1
= vmm – v
| = - 6 | × 12 | |
| 603 |
= (6 – 5.97)v = 0.03 v = 30mv
