Railway Science (Physics-Fluid Mechanics)

Total Questions: 12

11. When an object is immersed in water, its weight reduces from 4 N in air to 2 N in water. Calculate the amount of buoyant force acting on an object in water. [[RRB Group D 23/10/2018 (Afternoon)]]

Correct Answer: (c) 2 N
Solution:

Given that, The weight of the body in the air = 4 N.
When immersed in water, the weight of the body = 2N.
In water, there will be a buoyancy force which opposes the weight of the body. Therefore the buoyant force is equal to = 4N - 2N = 2N.

12. What amount of water can reach a height of 10 m by a pump of 1 kW in a minute ? (Take g = 10 m/s²) [[RRB Group D 07/12/2018]

Correct Answer: (b) 600 kg
Solution: