(A): The dipolemoment value of ${\mathrm{NH}}_3$ is greater than zero
(R) : In ${\mathrm{NH}}_3$ bond angle is approximately ${104}^0$

(A): it is given that the dipole moment value of ammonia is greater than zero. $4.90\times {10}^{-30} \mathrm{cm}$ > 0. 

 (R): it is given that in ammonia bond angle is approximately 104°. But the bond angle of ammonia is $107°$. Therefore, Reason is False