# Mechanical Engineering - Compressors, Gas Dynamics and Gas Turbines - Discussion

Discussion Forum : Compressors, Gas Dynamics and Gas Turbines - Section 1 (Q.No. 9)
9.
In a jet propulsion
the propulsive matter is ejected from within the propelled body
the propulsive matter is caused to flow around the propelled body
its functioning does not depend upon presence of air
none of the above
Explanation:
No answer description is available. Let's discuss.
Discussion:
12 comments Page 1 of 2.

Scientist atanu said:   3 years ago
Jet propulsion is the propulsion of an object in one direction, produced by ejecting a jet of fluid in the opposite direction. By Newton's third law, the moving body is propelled in the opposite direction to the jet. Reaction engines operating on the principle of jet propulsion include the jet engine used for aircraft propulsion, the pump-jet used for marine propulsion, and the rocket engine and plasma thruster used for spacecraft propulsion. Biological systems include the propulsion mechanisms of certain marine animals such as cephalopods, sea hares, arthropods, and fish.

So, B is correct.

Mechvirus said:   4 years ago
Option B is correct because the jet propulsion matter flows around the jet body.

Rocket propulsion is ejected the propulsion and rocket fly forward.

Aki said:   5 years ago
But the exhaust of a jet engine never flows around the engine. It is expelled at the back of the engine producing thrust.

Suresh raj k said:   6 years ago
Explain how the option B is correct?

Dr. Jayant Sinha said:   6 years ago
Any jet engine works on air flowing across its engine. The option A is limited to Rocket engine only. When its Jet propulsion its option B.

Mahesh said:   6 years ago
A is the correct option.

AshokAshok Aj said:   7 years ago
Option B is for Turbo jet engines.

Ajay said:   7 years ago
I think option A is for Rocket Propulsion, so I think option B is Right.

Thamu said:   7 years ago
For example, take rocket as propelled body, is it right that propulsive matter is made to flow around the body. Answer A is correct.

Vilas said:   7 years ago