Practice Pakistan's most useful MCQs for competitive exams

In the laminar boundary layer flow over a flat plate, the ratio (δ/x) varies as: (where, ‘δ’ is the boundary layer thickness and ‘x’ is the distance from the leading edge in the direction of flow)?

• (A)  Re
• (B)  √Re
• (C)  1/Re
• (D)  Re-1/2

Answer

Submitted By :Ali Uppal

In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where, T = absolute temperature) ?

• (A)  1/√T
• (B)  1/T
• (C)  √T
• (D)  T

Answer

Submitted By :Ali Uppal

With increase in the ratio of orifice diameter to pipe diameter, the fraction of the orifice pressure differential that is permanently lost________________?

• (A)  Increases
• (B)  Decreases
• (C)  Remains unchanged
• (D)  Increases exponentially

Answer

Submitted By :Ali Uppal

Acceleration head in a reciprocating pump_______________________?

• (A)  Increases the work done during delivery stroke
• (B)  Decreases the work done during suction stroke
• (C)  Does not change the work requirement of the pump
• (D)  Increases the work done during suction stroke

Answer

Submitted By :Ali Uppal

A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is__________________?

• (A)  20 m/sec
• (B)  10 m/sec
• (C)  5 √2 m/sec
• (D)  5 m/sec

Answer

Submitted By :Ali Uppal

A fluid whose apparent viscosity increases with shear rate is termed as the _____________ fluid?

• (A)  Newtonian
• (B)  Viscous
• (C)  Dilatant
• (D)  Non-viscous

Answer

Submitted By :Ali Uppal

In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the _____________ efficiency?

• (A)  Manometric
• (B)  Mechanical
• (C)  Volumetric
• (D)  Overall

Answer

Submitted By :Ali Uppal

Very small pressure difference (< 5 mm water column) can be most conveniently measured by a/an _____________ manometer?

• (A)  U-tube water
• (B)  U-tube mercury
• (C)  Inclined tube mercury
• (D)  Inclined tube water

Answer

Submitted By :Ali Uppal

The flow of a liquid through tapering pipe at a constant rate is an example of _______________ flow?

• (A)  Steady uniform
• (B)  Steady non uniform
• (C)  Unsteady uniform
• (D)  Unsteady non uniform

Answer

Submitted By :Ali Uppal

The centre of pressure is_________________?

• (A)  Always below the centroid of the area
• (B)  Always above the centroid of the area
• (C)  A point on the line of action of the resultant force
• (D)  At the centroid of the submerged area

Answer

Submitted By :Ali Uppal