NTA Abhyas JEE Main2020PhysicsMechanical Properties of FluidsPractice
A manometer connected to a close tap reads 3.5 × 10 5 N m - 2 . When the valve is opened, the reading of manometer falls to 3.0 × 10 5 N m - 2 , then velocity of flow of water is
Options
- A100 m s - 1
- B10 m s - 1
- C1 m s - 1
- D10 10 m s - 1
Correct answer
B. 10 m s - 1
Step-by-step solution
Bernoulli's theorem for unit mass of liquid P ρ + 1 2 v 2 = c o n s t a n t As the liquid starts flowing , it pressure energy decreases 1 2 v 2 = P 1 - P 2 ρ ⟹ 1 2 v 2 = 3.5 × 10 5 - 3 × 10 5 10 3 ⟹ v 2 = 2 × 0.5 × 10 5 10 3 ⟹ v 2 = 100 ⟹ v = 10 m s - 1