WHY SUCROSE DOES NOT GIVE MUTA ROTATION ?

Mutarotation is defined as the spontaneous change in the specific rotation of the optically active compound. This can occur only if there is a free OH group present on anomeric carbon atom (i.e. there is a free aldehydic or ketonic group present). 

As sucrose is a non reducing sugar (because the OH groups at the both the anomeric carbon atoms are involved in a bond)

it will ot undergo mutarotation. Also it will not give Benedict's test, Fehling's test and tollen's test, which is given readily by most of the aldehydes.