## Fluid Mechanics Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will

Increase
Remain unchanged
Data insufficient to predict relative pressure drop
Decrease

## Fluid Mechanics In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of

Relative roughness
Absolute roughness
Friction co-efficient for flows at equal Reynold number
All of these

## Fluid Mechanics Vane anemometer

Rotates an element at a speed determined by the velocity of the fluid in which the meter is immersed
Is an area meter
None of these

## Fluid Mechanics A stream line is

Always the path of particle
Drawn normal to the velocity vector at every point
Fixed in space in steady flow
A line connecting the mid points of flow cross-section

## Fluid Mechanics Power number is the ratio of

Drag stress to inertial stress
Gravitational stress to drag stress
Inertial stress to gravitational stress
Inertial stress to drag stress

M is below G
M & G coincide
M is above G
None of these