Of the following quantities,which one has dimensions different from the remaining three?

The ratio $\left(\frac{E}{W}\right)$ of relative strength of electromagnetic force $(E)$ to weak nuclear force $(W)$ is,

Which two of the following five physical parameters have the same dimensions $?$
$(1)$ energy density
$(2)$ refractive index
$(3)$ dielectric constant
$(4)$ Young's modulus
$(5)$ magnetic field

Identify the incorrect statement.

Which of the following groups has different dimensions?

To determine the Young's modulus of a wire,the formula is $Y = \frac{FL}{A\Delta L}$,where $L$ is the length,$A$ is the area of cross-section of the wire,and $\Delta L$ is the change in length of the wire when stretched with a force $F$. The conversion factor to change the unit of Young's modulus from $CGS$ to $MKS$ system is $x \times 10^{-1} \ N/m^2$. Find the value of $x$.