Which conditions are mandatory to get satisfied for the formation of a sphere ? (Marks : 01)

 a. 0 ≤ θ ≤ π , 0 ≤ Ф ≤ 2 π & r = constant

b. Ф = change , r = change & θ = constant

c. r → ∞ , 0 ≤ θ ≤ 2π & Ф = constant

d. Ф → ∞ , 0 ≤ θ ≤ 2π & r= constant

ANSWER: 0 ≤ θ ≤ π , 0 ≤ Ф ≤ 2 π & r = constant

Explanation:

A sphere is formed only when the value of an angle vector originated due to Z-axis and radius vector lies between zero and π; and the value of angle vector between X-axis & radius vector projection over XY plane is greater than zero but less than or equal to 2π ,by keeping radius vector as a constant