Question

The order of the differential equation of all circles of radius r, having centre on y-axis and passing through the origin is

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (A)

1

Answer 2

The equation of the circle will be $x^{2} + (y \pm r)^{2} = r^{2}$.

Hence the constant to be eliminated is r.

∴ order of differential equation =1