The dipole moment of phenol is smaller than that of methanol. Why?
In phenol carbon is sp2 hybridized and due to this reason benzene ring is producing electron withdrawing effect.
On the other hand, carbon of methanol is sp3 hybridized and produces electron releasing effect (+ effect) Thus. C - O bond in phenol is less polar than C - O bond in methanol and therefore, the dipole moment of phenol (1.54 D) is smaller than that of methanol (1.71 D).