Basics of Circle

IMPORTANT

Basics of Circle: Overview

This topic covers concepts such as Circle, Equation of Circle, Equation of Circle in General Form, Equation of Circle in Diameter Form, Equation of Circle in Parametric Form, and Equation of Circle Passing through Three Points.

Important Questions on Basics of Circle

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IMPORTANT

Tangents drawn from the point P(1, 8) to the circle 

x2+y2-6x-4y-11=0

touch the circle at the points A and B. The equation of the circumcircle of the triangle PAB is

HARD
IMPORTANT

Extremities of a diagonal of a rectangle are 0, 0 and 4, 3. Find the equation of the tangents to the circumcircle of a rectangle which are parallel to this diagonal.

HARD
IMPORTANT

The circle Cx2+y2+kx+1+ky-k+1=0 passes through two fixed points for every real number K. The minimum value of the radius of circle C is

HARD
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If a circle passes through the points of intersection of the coordinate axes with the lines   λxy+1=0andx2y+3=0 , then the value of   λ is:

EASY
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If A and B are fixed points in the plane such that PA PB =k  (constant) for all P on a given circle, then the value of k cannot be equal to:

EASY
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The equation of a circle with centre at 2,2 and passes through the point 4,5 is

EASY
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The equation of a circle with center at -2, 3 and circumference of 4π units is

MEDIUM
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If two diameters of a circle of circumference 10π lie along the lines 2x+3y+1=0 and 3x-y-4=0, then the equation of circle is

MEDIUM
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If (4, 7) and (-2, -1) are ends of a diameter of a circle which intersects X-axis at A and B, then AB is equal to _________

MEDIUM
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The equation of a circle with centre on y-axis and passing through the origin and the point (3, 4) is

HARD
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The number of integer values of k for which the equation x2+y2+k-1x-ky+5=0 represents a circle whose radius cannot exceed 3, is

MEDIUM
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Let C be the circle whose diameter is the line segment formed by the line 3x+2y=6 intercepted by the coordinate axes. Then C also passes through the point.

MEDIUM
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The equation of the circle whose centre lies on the line 2x+y=0 and touching the lines 4x-3y+10=0 and 4x-3y-30=0 is

MEDIUM
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If the equation of the circumcircle of an equilateral triangle is x2+y2-10 x+12 y+45=0, the area of the triangle is

MEDIUM
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If the equation of the incircle of a triangle is 2x2+2y2+5x+y-15=0 then the area of the triangle is

MEDIUM
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The length of a side of the equilateral triangle inscribed in the circle x2+y2=a2 is

MEDIUM
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The length of the intercept made by the circle x2+y2-6x-2y-7=0 on the x-axis is

HARD
IMPORTANT

The length of the chord parallel to y-axis of the circle x2+y2-6x-8y-9=0 is

HARD
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The equation of the incircle of the triangle formed by the straight line 4x+3y=6 with the coordinate axes is

MEDIUM
IMPORTANT

If the coordinates of one end-point of a diameter of the circle x2+y2-8x-4y+15=0 are (2, 1), the coordinates of its other end are