Which form of energy is most useful for propulsion?

The kinetic energy of ejected matter

The electrical energy of the rocket control system

The chemical energy of combustion of propellants

The potential energy of the rocket at some altitude

Correct Answer : The kinetic energy of ejected matter

Explanation : At the nozzle exit, the exhaust gases are ejected with some kinetic energy. This is the most useful form of energy crucial to propulsion. Chemical energy produced from the combustion of propellants is of no use unless it can be harnessed for propelling the rocket forward by some means.

Recently Updated in Rocket Propulsion Questions

In which of the propulsion systems is the maximum temperature achieved?

Nuclear

Chemical

Arc heating

Solar heating

Correct Answer : Option (C) : Arc heating

Explanation : Arc heating can lead to temperatures of about 20,000 deg C. Chemical propulsion systems have a maximum temperature ranging from 2500-4100 deg C, while nuclear fission leads to temperatures of about 2700 deg C.

What is the propulsion duration of resistojets?

Few weeks

Few days

Few minutes

Few seconds

Correct Answer : Option (B) : Few days

Explanation : Resistojets have a propulsion duration spanning a few days. The chemical rocket engines have a propulsion duration lasting a few seconds to a few minutes, while for ion-electrostatic engines, it lasts for months.

Which of the following engines can achieve the maximum specific impulse of 5000 s?

Hall effect

Ion-electrostatic

Solar heating

Nuclear fission

Correct Answer : Option (B) : Ion-electrostatic

Explanation : Ion-electrostatic engine has a specific impulse of 1200-5000 s. Nuclear fission type engines have Isp of 500-860 s, while solar heating engines have it around 400-700 s.