A modelof a hydraulic turbine is tested at a head of 1/4™ of that under which the full scale turbine works. The diameter of the modelis half of that of the full scale turbine. if N is the RPM of the full scale turbine, then RPM of the modelwill be

A

$$\frac{N}{4}$$

B

$$\frac{N}{2}$$

C

N

D

2N