Question

Which one of the following is not related to solid propellant rocket?

• A. high density
• B. control over oxidizer to fuel ratio (O/F) once ignited
• C. simple in construction
• D. specific impulse in the range of 210–290 s

Hint:

Solid rockets are reliable but offer no throttle or mixture control.

Answer 1

The Correct Option is B

Solid propellant rockets are known for their simplicity in construction, high density, and specific impulse ranging from 210 to 290 seconds. However, once a solid propellant rocket is ignited, it does not allow for control over the oxidizer to fuel ratio (O/F). This is due to the nature of the propellant mixture being pre-bonded and pre-set before ignition, unlike liquid propellant rockets that allow for adjusting the O/F ratio during flight.

The option control over oxidizer to fuel ratio (O/F) once ignited is not applicable to solid propellant rockets as they lack the capability to alter the O/F ratio once the reaction has commenced. It is a specific characteristic of solid propulsion systems that they burn at a fixed rate determined by the composition and geometry of the propellant.

Characteristic	Solid Propellant Rocket
High Density	Yes
Control over O/F once ignited	No
Simple in Construction	Yes
Specific Impulse (210-290s)	Yes

Thus, the option control over oxidizer to fuel ratio (O/F) once ignited is the correct answer as it is not a characteristic of solid propellant rockets.