Fluid Mechanics MCQs

501. Momentum correction factor used in fluid flow problems accounts for the

Change in direction of flow

Change in total energy

Change in pressure

Non uniform direction of velocities at inlet & outlet sections

✅ The correct answer is option D.

502. Euler’s equation of motion states, that at every point, the

Fluid momentum is constant

Force per unit mass equals acceleration

Rate of mass outflow is equal to the rate of mass inflow

None of these

✅ The correct answer is option B.

503. Power number is the ratio of

Drag stress to inertial stress

Inertial stress to drag stress

Inertial stress to gravitational stress

Gravitational stress to drag stress

✅ The correct answer is option A.

504. The percentage slip in a reciprocating pump set is given by the % of (where, Q₁ = actual discharge Q₂ = theoretical discharge)

Q₁/Q₂

Q₂/Q₁

(Q₂ – Q₁)/Q₁

(Q₂ – Q₁)/Q₂

✅ The correct answer is option D.

505. The value of critical Reynolds number for pipe flow is

1300

10,000

100,000

None of these

✅ The correct answer is option A.

506. Transition length for a turbulent fluid entering into a pipe is around __________ times the pipe diameter.

5

50

500

1000

✅ The correct answer is option B.

507. Major loss in sudden contraction in pipe flow is due to

Boundary friction

Flow contraction

Expansion of flow after sudden contraction

None of these

✅ The correct answer is option B.

508. For ideally incompressible fluid, the Mach number will be

1.5

1

0

5

✅ The correct answer is option B.

509. With increase in the schedule number of a pipe of a particular nominal size, the

Wall thickness also increases

I.of the pipe decreases

O.of the pipe remains constant

All of the above

✅ The correct answer is option D.

510. Gear pump

Is a positive displacement pump

Is a centrifugal pump

Is a non-positive displacement pump

Can be started with delivery valve closed

✅ The correct answer is option A.