When a rectangular bar of length $$l$$, breadth b and thickness t is subjected to an axial pull of P, then linear strain ($$\varepsilon $$) is given by (where E = Modulus of elasticity)

A. $$\varepsilon = \frac{{\text{P}}}{{{\text{btE}}}}$$

B. $$\varepsilon = \frac{{{\text{btE}}}}{{\text{P}}}$$

C. $$\varepsilon = \frac{{{\text{bt}}}}{{{\text{PE}}}}$$

D. $$\varepsilon = \frac{{{\text{PE}}}}{{{\text{bt}}}}$$

Answer: Option A