The dimensional formula for Young's modulus is

In which case is there maximum extension in the wire,if the same force is applied to each wire?

Two rods of different materials having coefficients of linear expansion $\alpha_1, \alpha_2$ and Young's moduli $Y_1$ and $Y_2$ respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If $\alpha_1 : \alpha_2 = 2 : 3$,and the thermal stresses developed in the two rods are equal,then the ratio $Y_1 : Y_2$ is equal to:

In a tensile test on a metal bar of diameter $0.015 \ m$ and length $0.2 \ m$,the relation between the load and elongation within the proportional limit is found to be $F = 97.2 \times 10^6 (\Delta L)$,where $F$ is the load in $N$ and $\Delta L$ is the elongation in $m$. The Young's modulus of the material in $GPa$ is:

In a wire of length $L,$ the increase in its length is $l.$ If the length is reduced to half,the increase in its length will be

Write the equation of bending in a rod. Write the unit of bending and its dimensional formula.