501.In Gypsum bonded investment,composition of alpha hemihydrate is

a.60-65%
b.30-35%
c.5-10%
d.85-90%

Ans-b.30-35%
Explanation-Composition of gypsum bonded investment is 
Silica-60-65%
Alpha hemihydrate-30-35%
Modifiers-5%

500.All of the following are tumour supressor genes except

a.WT -1
b.PTEN
c.NF-2
d.RAS

Ans-d.RAS

499.A diamond in the shape of square based pyramid is used in

a.Knoop hardness test
b.Vicker hardness test
c.Shore and Barcol test
d.Rock well hardness test

Ans-b.Vicker hardness test