Question

The bhagirathi and the Alaknanda merge at Deoprayag to form the Ganga with their speeds in the ratio 1 :1.5. The cross-sectional areas of the Bhagirathi, the Alaknanda and the Ganga are in the ratio 1 : 2 :3. Assuming stremline flow, the ratio of the speed of Ganga to that of the Alaknands is

(A) 7 : 9

(B) 4 :3

(C) 8 : 9

(D) 5 :3

Answer 1

Correct Option :- (C) 8 : 9

Explanation :-

By equation of continuity

Area of Bhagirathi ⇒A

Area of Alaknanda ⇒2A

Area of Ganga ⇒3A