
In CHCl3, dipole moment of C−H is added to the resultant dipole moment of three C−Cl bonds, hence compound has non-zero value of dipole moment.
Electronegativity of carbon =2.5
Electronegativity of hydrogen=2.1.

Elelctrongegativity of C=2.5
Electronegativity of Cl=3

Due to symmetry and similar bonds, vector summation of net dipole moments of both CH4,CCl4 are zero, hence equal.