Answer:
The Dipole moment is 6.77 Debyes.
Explanation:
Given bond length of HBr molecule = 1.41 A°,
We also know charges on H and Br(+1 and -1 respectively)
Charge on H = (+1)
(absolute charge of electron);
Charge on Br = (-1)
(absolute charge of electron);
Since absolute charge on electron =
;
Therefore charge on H =
Coulomb;
charge on Br = 
We know Dipole Moment = Charge
Distance;
Here,
Distance = Bond Length = 1.41 A° = 1.41
;
and charge on atom =
Coulomb;
Therefore,
Dipole Moment = Distance
Charge
Dipole Moment =
;
Dipole Moment =
SI units.
The conversion factor of for SI units to Debye is 2.9989 
Therefore,
Dipole Moment = 2.25882 
Dipole Moment = 6.77 Debye.