A jet engine works on the principle of conservation of:

Question

Question

This question was previously asked in

Bihar CET B.Ed Official Paper (Held On: 25 Jun, 2024)

Answer 1

The correct answer is Linear Momentum.

Key Points

A jet engine operates on the principle of linear momentum conservation, which states that the total momentum of a system remains constant when no external forces act on it.
In a jet engine, air is compressed, mixed with fuel, ignited, and then expelled at high speed, resulting in the forward motion of the engine (thrust).
The high-speed exhaust gases ejected from the engine create an equal and opposite reaction (thrust), following Newton’s Third Law of Motion, which is directly related to the conservation of linear momentum.
This principle is key in the functioning of all propulsion systems, including jet engines, rockets, and other vehicles that rely on expelled gases to generate movement.

Additional Information

Linear Momentum: The product of an object's mass and velocity. The law of conservation of linear momentum states that in a closed system, the total momentum before and after an event is the same, provided no external forces act.
The operation of a jet engine is a classic example of Newton's Third Law of motion, which states that for every action, there is an equal and opposite reaction. The expulsion of exhaust gases (action) results in the movement of the jet in the opposite direction (reaction).
Jet engines, including turbofans and turbojets, rely on the rapid expulsion of air to generate thrust, which is essentially a direct application of linear momentum conservation.
In contrast, angular momentum deals with rotational motion, and while it is crucial in systems like turbines, it is not the primary principle behind jet engine operation.
Energy conservation also plays a role in jet engines, particularly in terms of fuel efficiency and thermal management, but linear momentum is the primary principle for generating thrust.
Mass-velocity and mass-energy conservation principles are also important in various physical systems but do not directly apply to the propulsion mechanism in jet engines.