In the circuit shown in the figure, the resistances R and R' change due to strain. While R increases, R' decreases by the same amount ΔR due to the applied strain. The unstrained values of R and R' are 100 Ω each. If same strain is applied to all the resistors, and the output voltage (Vab) changes to 0.3 V, then ΔR is closest to
1
3 Ω
2
1.5 Ω
3
4.5 Ω
4
6 Ω