KEAM 2014 Physics and Chemistry Paper

Species having 4 bp and 0 lp or 3 bp and 1 Ip or 2 bp and 2Ip are generally sp3 hybridised.
NH4+⇒4bp+0lp=sp3 hybridised
BF3⇒3bp+olp⇒sp2 hybridised
SF6⇒6bp+Olp=sp2d2 hybridised
PCl5⇒5bp+0Ip=sp3d hybridised
XeF4⇒4bp+2Ip=sp3d2 hybridised
Thus, NH4+ is the species, central atom of which is sp3 hybridised.