Centre and Radius of a Circle - Basic Quiz

Centre and Radius of a Circle - Basic Quiz

Dear Readers,

Mathematics is an important subject in SSC,DSSB & Other Exams. .

Q1. The area of the circle whose centre is at (1, 2) and which passes through the point (4, 6) is :

•  5pi
•  10pi
•  25pi
•  None of these

Solution
25pi

Q2.The centres of the circles x^2+y^2=1,x^2+y^2+6x-2y=1 and x^2+y^2-12x+4y=1 are :

•  Same:
•  Collinear
•  Non-collinear
•  None of these

Solution
Collinear

Q3.  If a circle passes through the point (0, 0), (a, 0), (0, b), then its centre is :

•  (a, b)
•  (b,a)
•  (a/2,b/2)
•  (b/2,-a/2)

Solution
(a/2,b/2)

Q4. If the radius of the circle x^2+y^2-18x+12y+k=0 be 11, then k =

•  347
•  4
•  -4
•  49

Solution
-4

Q5.The centre and radius of the circle 2x^2+2y^2-x=0 are

•  (1/4,0) and 1/4
•  (-1/2,0) and 1/2
•  (1/2,0) and 1/2
•  (0,-1/4) and 1/4

Solution
 (1/4,0) and 1/4

Q6. Centre of the circle (x-3)^2+(y-4)^2=5 is

•  (3, 4)
•  (-3, -4)
• (4, 3)
•  (-4, -3)

Solution
(3, 4)

Q7.A circle has its equation in the form x^2+y^2+2x+4y+1=0. Choose the correct coordinates of its centre and the right value of its radius from the following

•  Centre (– 1, –2), radius = 2
•  Centre (2, 1), radius = 1
•  Centre (1, 2), radius = 3
•  Centre (– 1, 2), radius = 2

Solution
Centre (– 1, –2), radius = 2

Q8.71. A circle touches the axes at the points (3, 0) and (0, – 3). The centre of the circle is

•  (3, – 3)
•  T(0, 0)
•  (– 3, 0)
•  (6, – 6)

Solution
(3, – 3)

Q9.Radius of the circle x^2+y^2+2x cos⁡θ+2y sin⁡θ-8=0, is

•  1
•  3
•  r^2
•  √10

Solution
3

Q10. The area of a circle whose centre is (h, k) and radius a is

•  π(h^2+k^2-a^2)
•  πa^2 hk
•  πa^2
• None of these

Solution
πa^2