Fluid Mechanics MCQs Archives

541. For a fluid rotating at constant angular velocity about vertical axis as a rigid body, the pressure intensity varies as the

Square of the radial distance

Radial distance linearly

Inverse of the radial distance

Elevation along vertical direction

✅ The correct answer is option A.

542. In turbulent flow, a rough pipe has the same friction factor as a smooth pipe

In the zone of complete turbulence

When the roughness projections are much smaller than the thickness of the laminar film

Everywhere in the transition zone

When the friction factor is independent of the Reynold’s number

✅ The correct answer is option B.

543. The dimension of surface tension is

ML⁻²

MT⁻²

MLT⁻²

ML⁻²T

✅ The correct answer is option B.

544. Erosion and pits formation on the impeller of a centrifugal pump may be due to

Cavitation

Low speed of impeller

Its operation with delivery valve closed for considerable time after starting the pump

Off centering of pump with motor

✅ The correct answer is option A.

545. Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor.

Less than

More than

Same as

None of these

✅ The correct answer is option B.

546. The actual velocity at vena-contracta for flow through an orifice from a reservoir is given by

Cv . √(2gH)

Cc . √(2gH)

Cd . √(2gH)

Cv . Va

✅ The correct answer is option A.

547. The energy loss over a length of pipeline according to Darcy-Weisbach equation for pipe flow is _________ the mean velocity of flow.

Directly proportional to

Directly proportional to square of

Inversely proportional to

Inversely proportional to square of

✅ The correct answer is option B.

548. A gas

Signifies absence of density

Can resist shearing action

Is incompressible

Is a supercritical vapor

✅ The correct answer is option D.

549. If the discharge of a centrifugal pump is throttled, then its suction lift

Increases

Decreases

Remains unchanged

Data insufficient to predict

✅ The correct answer is option A.

550. The energy loss in flow through ven-turimeter is less than that through flow nozzle, because in case of a flow nozzle, the

Length is shorter

Throat diameter is more

Sudden expansion of flow in the downstream occurs

Distance between the throat and the inlet is more

✅ The correct answer is option C.