Fluid Mechanics
JKSSB Junior Engineer (Mechanical) · Fluid Mechanics & Machinery · 69 practice questions with answers and explanations: 37 Easy, 32 Medium, 0 Hard.
Sample questions
Sample Easy question 1
Newton's law of viscosity states that shear stress is proportional to:
- The velocity gradient
- The density
- The temperature
- The pressure
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Answer: A. τ = μ (du/dy).
Sample Easy question 2
Pascal's law states that pressure applied to a confined fluid is:
- Transmitted equally in all directions
- Transmitted only downwards
- Lost through the walls
- Doubled at the bottom
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Answer: A. This is the principle behind the hydraulic jack and press.
Sample Easy question 3
A venturimeter is used to measure:
- Pressure in a tank
- The flow rate through a pipe
- Viscosity
- Temperature of the fluid
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Answer: B. It uses the pressure drop across a converging throat.
Sample Medium question 4
The specific speed of a turbine is the speed of a geometrically similar turbine that develops:
- unit power under unit head
- unit discharge under unit head
- unit power at unit discharge
- unit head at unit speed
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Answer: A. Turbine specific speed Ns = N√P / H^(5/4).
Sample Medium question 5
The draft tube of a reaction turbine is provided to:
- recover kinetic energy and increase the effective head
- increase the flow rate by suction only
- reduce the runner diameter
- act as a governor
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Answer: A. It discharges water gradually and allows the turbine to be set above the tail water.
Sample Medium question 6
The overall efficiency of a hydraulic turbine is the ratio of:
- the water power to the shaft power
- the shaft power to the power available from the water
- the runner power to the shaft power
- the head to the discharge
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Answer: B. Overall efficiency = brake (shaft) power / water power.