A Wheatstone bridge used to make a musical instrument from a strain gauge (resistor R1 ) attached to a metal bar and three other strain gauges used as fixed resistors on the circuit board. When the bar is struck, the strain causes changes in R1 only. The change in resistance is Δ R1 =0.2 Ω per microstrain (i.e. 0.2 Ω for a strain of ε= 10-6) and the initial value of R1 is 119 Ω.
Vs =0.7 V, R2 =119 Ω, R3 =122 Ω and R4 =122 Ω.
(iii) When the bar is struck it oscillates with a maximum strain of 5 x 10−6 . Given that this varies the value of R1 by 1 Ω, complete these calculations for the minimum and maximum output voltage. Please give your answer to four decimal places.
VAB
(min) = ?V
(max) = ?V
Please fix the following input errors: