Dimensional formula $M{L^{ - 1}}{T^{ - 2}}$ does not represent the physical quantity

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

The dimensions of calorie are

Give an example of
$(a)$ a physical quantity which has a unit but no dimensions
$(b)$ a physical quantity which has neither unit nor dimensions
$(c)$ a constant which has a unit
$(d)$ a constant which has no unit

Plane angle and solid angle have :

Which of the following pair does not have similar dimensions