Home
Current Affairs January 2024

What is the correct answer?

4

The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by

A. [2(Vr - v) v]/ Vr²

B. 2(Vr + v) v]/ Vr²

C. [(Vr - v) v]/ Vr

D. [(Vr + v) v]/ Vr

Correct Answer :

A. [2(Vr - v) v]/ Vr²


Related Questions

What is the correct answer?

4

According to fan laws, at constant speed and capacity, the pressure and power vary

A. Directly as the air or gas density

B. Inversely as square root of density

C. Inversely as density

D. As square of density

What is the correct answer?

4

Overall efficiency of a centrifugal pump is the ratio of

A. Energy available at the impeller to the energy supplied to the pump by the prime mover

B. Actual workdone by the pump to the energy supplied to the pump by the prime mover

C. Energy supplied to the pump to the energy available at the impeller

D. Manometric head to the energy supplied by the impeller per kN of water

What is the correct answer?

4

The specific speed of a hydraulic turbine depends upon

A. Speed and power developed

B. Discharge and power developed

C. Speed and head of water

D. Speed, power developed and head of water

What is the correct answer?

4

The power produced by the reaction turbine is ________ to the head of water.

A. Directly proportional

B. Inversely proportional

C. 4th power

D. None of these

What is the correct answer?

4

Pressure intensifier increases the pressure in proportion to

A. Ratio of diameters

B. Square of ratio of diameters

C. Inverse ratio of diameters

D. Square of inverse ratio of diameters

What is the correct answer?

4

A Pelton wheel is

A. Tangential flow impulse turbine

B. Inward flow impulse turbine

C. Outward flow impulse turbine

D. Inward flow reaction turbine

What is the correct answer?

4

The water in a jet propelled boat is drawn through the openings facing the direction of motion of the boat. The efficiency of propulsion is given by

A. 2V/(vr - v)

B. 2V/(vr + v)

C. V/(vr - v)

D. V/(vr + v)

What is the correct answer?

4

The ratio of actual work available at the turbine to the energy imparted to the wheel is known as ________ efficiency.

A. Hydraulic

B. Mechanical

C. Overall

D. None of these

What is the correct answer?

4

Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m.?

A. Pelton wheel

B. Francis turbine

C. Kaplan turbine

D. None of these

What is the correct answer?

4

Indicator diagram of a reciprocating pump is a graph between

A. Flow vs. swept volume

B. Pressure in cylinder vs. swept volume

C. Flow vs. speed

D. Pressure vs. speed

What is the correct answer?

4

Which of the following pump is preferred for flood control and irrigation applications?

A. Centrifugal pump

B. Axial flow pump

C. Mixed flow pump

D. Reciprocating pump

What is the correct answer?

4

The width of the bucket for a Pelton wheel is generally ________ the diameter of jet.

A. Double

B. Three times

C. Four times

D. Five times

What is the correct answer?

4

The depth of the bucket for a Pelton wheel is generally ________ the diameter of jet.

A. Equal to

B. 1.2 times

C. 1.8 times

D. Double

What is the correct answer?

4

A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit speed of the wheel is

A. 10 r.p.m.

B. 20 r.p.m.

C. 40 r.p.m.

D. 80 r.p.m.

What is the correct answer?

4

Discharge of a centrifugal pump is (where N = Speed of the pump impeller)

A. Directly proportional to N

B. Inversely proportional to N

C. Directly proportional to N²

D. Inversely proportional to N²

What is the correct answer?

4

The speed of an imaginary turbine, identical with the given turbine, which will develop a unit power under a unit head, is known as

A. Normal speed

B. Unit speed

C. Specific speed

D. None of these

What is the correct answer?

4

One horsepower is equal to

A. 102 watts

B. 75 watts

C. 550 watts

D. 735 watts

What is the correct answer?

4

The specific speed of a turbine is the speed of an imaginary turbine, identical with the given turbine, which

A. Delivers unit discharge under unit head

B. Delivers unit discharge under unit speed

C. Develops unit power under unit head

D. Develops unit power under unit speed

What is the correct answer?

4

In a centrifugal pump, the regulating valve is provided on the

A. Casing

B. Delivery pipe

C. Suction pipe

D. Impeller

What is the correct answer?

4

The discharge through a reaction turbine ________ with the increase in unit speed.

A. Decreases

B. Increases

C. Remain same

D. None of these

What is the correct answer?

4

Which of the following statement is correct?

A. In an impulse turbine, the water impinges on the buckets with pressure energy.

B. In a reaction turbine, the water glides over the moving vanes with kinetic energy.

C. In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure.

D. In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.

What is the correct answer?

4

When a piping system is made up primarily of friction head and very little of vertical lift, then pump characteristics should be

A. Horizontal

B. Nearly horizontal

C. Steep

D. First rise and then fall

What is the correct answer?

4

According to fan laws, for the fans having constant wheel diameters, the power demand varies

A. Directly as fan speed

B. Square of fan speed

C. Cube of fan speed

D. Square root of fan speed

What is the correct answer?

4

The force exerted by a jet of water (in a direction normal to flow) impinging on a fixed plate inclined at an angle θ with the jet is

A. waV/2g × sinθ

B. waV/g × sinθ

C. waV²/2g × sin2θ

D. waV²/g × sinθ

What is the correct answer?

4

Mechanical efficiency of a centrifugal pump is the ratio of

A. Energy available at the impeller to the energy supplied to the pump by the prime mover

B. Actual workdone by the pump to the energy supplied to the pump by the prime mover

C. Energy supplied to the pump to the energy available at the impeller

D. Manometric head to the energy supplied by the impeller per kN of water

What is the correct answer?

4

A hydraulic press is a device used

A. To store pressure energy which may be supplied to a machine later on

B. To increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure

C. To lift larger load by the application of a comparatively much smaller force

D. All of the above

What is the correct answer?

4

The flow ratio of Francis turbine is defined as the ratio of the

A. Velocity of flow at inlet to the theoretical jet velocity

B. Theoretical velocity of jet to the velocity of flow at inlet

C. Velocity of runner at inlet to the velocity of flow at inlet

D. None of the above

What is the correct answer?

4

Slip of a reciprocating pump is defined as the

A. Ratio of actual discharge to the theoretical discharge

B. Sum of actual discharge and the theoretical discharge

C. Difference of theoretical discharge and the actual discharge

D. Product of theoretical discharge and the actual discharge

What is the correct answer?

4

For 450 m head of water, _________ shall be used.

A. Pelton wheel

B. Kaplan turbine

C. Francis turbine

D. None of these

What is the correct answer?

4

A Pelton wheel working under a constant head and discharge, has maximum efficiency when the speed ratio is

A. 0.26

B. 0.36

C. 0.46

D. 0.56