Given, By using Stefan's law, P=σAeT4 where, P= power, σ‌‌=‌ Stefan's constant ‌ A‌‌=‌ area, ‌ e‌‌=‌ emissivity, ‌ ‌ and ‌‌‌T‌‌=‌ temperature. ‌ ∴‌‌[σ]‌‌=[‌
P
AeT4
]=[‌
ML2T−2
L2T1K4
]=[ML0T−3K−4]...‌ (i) ‌ Now, By Wien's displacement law, [λT]=‌ constant ‌=[b]=[M0L1K1]...‌ (ii) ‌ where, ‌λ=‌ wavelength, ‌ ‌T=‌ temperature, ‌ and b= Stefan's constant. Now, quadrating the power of Eq. (ii) and multiply by Eq. (i), we get ∴‌‌[σb4]‌‌=[ML0T−3K−4][M0L1K1]4 ‌‌=[ML0T−3K−4][M0L4K4] ‌‌=[M1L4T−3]