[amp_mcq option1=”When the star momentarily moves vertically” option2=”When the angle at the star of the spherical triangle is 90°” option3=”When the star” option4=”All the above” correct=”option1″]
The correct answer is A. When the star momentarily moves vertically.
A star is said to elongate when it momentarily moves vertically. This is because the star is actually a point of light, and when it moves vertically, it appears to elongate. This is similar to how a car’s headlights appear to elongate when they are moving towards you.
Option B is incorrect because the angle at the star of the spherical triangle is not always 90°. The angle at the star of the spherical triangle is the angle between the star and the horizon. This angle can be any value between 0° and 180°.
Option C is incorrect because the star does not always move vertically. The star can move in any direction, including horizontally.
Option D is incorrect because only option A is correct.