For a constant gas ejection velocity (v) of 1440 m/s and a mass flow rate (m) of 15 kg/s, find the power of the jet (Pjet).

7.78 MW

15.55 MW

31.10 MW

62.21 MW

Correct Answer : 15.55 MW

Explanation : Power of the jet is 1/2mv². It is the time rate of expenditure of ejected jet’s kinetic energy.
Pjet = 1/2 x 15 x 1440²
= 15.55 MW.

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

Nuclear

Chemical

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Correct Answer : Option (C) : Arc heating

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Few weeks

Few days

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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

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Correct Answer : Option (B) : Ion-electrostatic

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