Question

The equation $x^2+y^2=r^2$ represents a family of concentric circles centered at the ...$A$... and having ...$B$ ... radii.
Here, $A$ and $B$ are respectively

• A. origin, different
• B. $(1,1)$, different
• C. $(0,0)$, same
• D. $(1,1)$, same

Answer 1

Answer: (A)

Let us consider the equation
$x^2+y^2=r^2.....$(i)
By giving different values of $r$, we get different members of the family e.g., $x^2+y^2=1,x^2+y^2=4,x^2+y^2=9$, etc.

Thus, Eq. (i) represents a family of concentric circles centred at the origin and having different radii.