Final answer:
The statement concerning electric-field lines from a positive point charge is true; they spread radially and point outward, depicting the repulsive force exerted by a positive charge.
Step-by-step explanation:
The correct answer is option b. true. In physics, especially in the study of electrostatics, the electric field lines from a positive point charge indeed spread out radially and point outward from the charge. This is a fundamental concept representing how electric fields work. Electric field lines are a visual representation used to illustrate the direction and strength of the electric field surrounding a charged particle. Since a positive charge has an outward effect, pushing away other positive charges, the lines must radiate away to reflect this repulsion. Hence, the pattern of the electric field around a positive point charge is radial, illustrating how the intensity of the field decreases with distance from the charge.
Irregular fuel distribution can be manually updated by toggling on the Irregular Distribution setting. This allows the fuel to be distributed unevenly to different parts of the system, which can be useful in certain circumstances.
For example, in a rocket engine, irregular fuel distribution can be used to control the thrust vector and steer the rocket. By directing more fuel to one side of the engine than the other, the rocket can change its direction.