In the following molecules:
CH3Br, CH3F, CH3Cl, CH3I I , II , III , IV
The correct order of dipole moment will be:
III > II > I > IV
→μ=q×d
For CH3F, q is high but d is less and for CH3Cl, q is less but d is high and the net product of q and d is higher for CH3Cl.