Assertion (A) : In conventional impulse steam turbine designs, only two rows of moving blades are used in a Curtis stage.
Reason (R) : As the number of rows of moving blades in a Curtis stage increases, the effectiveness of the later rows decreases.
Option (A)
Both A and R are true and R is the correct explanation of A
Option (B)
Both A and R are true but R is NOT the correct explanation of A
A is true but R is false
A is false but R is true
Correct Option:
Question Solution:
Work done on last stages = 1/2n x total work where ‘n’ ® number of stages
Thus we see that as the number of moving blade row increases, the work developed by last row decreases. Therefore number of rows are limited and now a days than two rows are seldom used.