Question 1 :
What is the radius of the circle with the following equation?<br>$\displaystyle x^{2}-6x+y^{2}-4y-12=0$<br>
Question 2 :
The intercept on the line $y=x$ by the circle ${ x }^{ 2 }+{ y }^{ 2 }-2x=0$ is $AB$. Equation of the circle with $AB$ as a diameter is
Question 3 :
Find the value of a if $y^2=4ax $ pases through $(8,8)$
Question 4 :
The parabola $y = px^{2} + px + q$ is symmetrical about the line
Question 5 :
The radius of the circle centred at $(4,5)$ and passing through the centre of the circle ${x}^{2}+{y}^{2}+4x+6y-12=0$ is
Question 6 :
Assertion: If the equation of a circle is $(x+1)^2+(y-1)^2=4$, then its radius is 4.
Reason: Equation of a circle with radius r is given by, $(x-a)^2 + (y-b)^2=r^2$.
Question 7 :
The equation ${ x }^{ 2 }+{ y }^{ 2 }=9$ meets x-axis at 
Question 8 :
The equation to the circle with centre $(2,1)$ and touches the line $3x+4y-5$ is ?<br/>
Question 9 :
Equation of the circle with centre on y-axis and passing through the points $(1,0),(1,1)$ is:
Question 10 :
Find the equation of the circle passing through the origin and centre lies on the point of intersection of the lines $2x+y=3$ and $3x+2y=5$.
Question 12 :
State whether the following statements are true or false.<br/>The equation $x^{2}+y^{2} + 2x -10y + 30 = 0$ represents the equation of a circle.<br/>
Question 13 :
The length of the diameter of the circle ${x^2} + {y^2} - 4x - 6y + 4 = 0$
Question 14 :
Centres of the three circles<br/>${x}^{2}+{y}^{2}-4x-6y-14=0$ <br/>${x}^{2}+{y}^{2}+2x+4y-5=0$ and<br/>${x}^{2}+{y}^{2}-10x-16y+7=0$. The centres of the circles are:
Question 15 :
Find the equation of a circle with center $(0, 0)$ and radius $5$.<br/>
Question 16 :
Which of the following equations of a circle has center at (1, -3) and radius of 5?
Question 18 :
If the equation $ax^{2}+2(a^{2}+ab-16)xy+by^{2}2ax+2by-\sqrt[4]{2}=0$ represents a circle, the radius of the circle is
Question 19 :
If the vertices of a triangle are $(2, -2), (-1, -1)$ and $(5, 2)$ then the equation of its circumcircle is?
Question 20 :
If the lines $3x - 4y - 7 = 0$ and $2s - 3y - 5 = 0$ are two diameters of a circle of area $49\pi$ square units, the equation of the circle is-