The permeability of vacuum can be expressed as, µ0∝eambcchd =keambcchd Here, k is the proportionality constant. Substituting the dimensions of different physical quantities in the above expression, we get [MLT−2A−2]=[AT]a[M]b[LT−1]c[ML2T−1]d [MLT−2A−2]=[Mb+dLc+2dTa−c−dAa] The values of a,b c and d is calculated by comparing the power on both sides. a=−2 b+d=1 c+2d=1 a−c−d=−2 On solving the above equations we get, a=−2 b=0 c=−1 d=1 So, the permeability of free space can be expressed as, µ0=