Show dimensionally that is dimensionally correct

PHYSICS · Subjective · A Level · Physics · Measurements and their errors · Measurements and their errors

Problem

Show dimensionally that

Y=\frac{mgL}{\pi r^2\Delta l}

is dimensionally correct, where

Y

is Young's modulus of the wire material,

L

is the length of the wire,

mg

is the applied weight,

r

is the radius of the wire, and

\Delta l

is the increase in its length.