Steam expands in a turbine from 40 bar, $$ 500^\circ C$$ to 0.10 bar isentropically. Assuming ideal conditions, given enthalpy drop 1198.8 kJ/kg, nozzle angle $$16^\cir$$ and N as 300 rpm. Mean diameter of the wheel,if the turbine were of simple impulse stage, will be

A

3.73 m

B

4.73 m

C

5.63 m

D

4.96 m