Mechanical Engineering

Question: In a reaction turbine, the draft tube is used
[A].

to run the turbine full

[B].

to prevent air to enter the turbine

[C].

to increase the head of water by an amount equal to the height of the runner outlet above the tail race

[D].

to transport water to downstream

Answer: Option C

Explanation:

No answer description available for this question.

Question: In a reaction turbine, the pressure head of water, while flowing over the vanes, is converted into kinetic head before leaving the wheel.
[A].

Agree

[B].

Disagree

Answer: Option B

Explanation:

No answer description available for this question.

Question: In a reaction turbine, the water enters the wheel under pressure and flows over the vanes.
[A].

Correct

[B].

Incorrect

Answer: Option A

Explanation:

No answer description available for this question.

Question: A double overhung Pelton wheel has
[A].

two jets

[B].

two runners

[C].

four jets

[D].

four runners

Answer: Option B

Explanation:

No answer description available for this question.

Question: If Hg is the gross or total head and hf is the head lost due to friction, then net or effective head (H) is given by
[A].

H = Hg/hf

[B].

H = Hg x hf

[C].

H = Hg + hf

[D].

H = Hg – hf

Answer: Option D

Explanation:

No answer description available for this question.

Question: In an impulse turbine, the pressure of water both at entering and leaving the vanes, is atmospheric.
[A].

Agree

[B].

Disagree

Answer: Option A

Explanation:

No answer description available for this question.

Question: An impulse turbine is used for
[A].

low head of water

[B].

high head of water

[C].

medium head of water

[D].

high discharge

Answer: Option B

Explanation:

No answer description available for this question.

Question: In an impulse turbine, the jet of water impinges on the bucket with a low velocity and after flowing over the vanes, leaves with a high velocity.
[A].

True

[B].

False

Answer: Option B

Explanation:

No answer description available for this question.

Question: A Pelton wheel is
[A].

tangential flow impulse turbine

[B].

inward flow impulse turbine

[C].

outward flow impulse turbine

[D].

inward flow reaction turbine

Answer: Option A

Explanation:

No answer description available for this question.

Question: Braking jet in an impulse turbine is used
[A].

to break the jet of water

[B].

to bring the runner to rest in a short time

[C].

to change the direction of runner

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.