Ekalavya - Conic Sections - Questions
Ekalavya - Conic Sections - Questions
Ekalavya - Conic Sections - Questions
Question 1: The radius of a circle passing through the focus of parabola x2 = 4 y and
touching it at the point ( 6, 9) is _____.
Options:
(a) 5
(b) 5 10
(c) 5 5
(d) 10
Question 3: A series of ellipses are described with given focus and corresponding directrix.
The locus of the extremities of their minor axes is _____.
Options:
(a) pair of straight line
(b) circle
(c) parabola
(d) ellipse
5 3
Question 4: Let 5 x − 3 y = 8 2 be the normal at the point P , to the ellipse
2 2
x2 y 2
+ = 1, a b . If M, M are the feet of the perpendiculars from the foci S, S
a 2 b2
respectively on the tangent at P, then the point of intersection of SM and SM is _____.
Options:
5
(a) , 0
2
5
(b) 0,
2
41 3
(c) ,
10 2 2 2
3 41
(d) ,
2 2 10 2
Question 5: The locus of the centre of the rectangle formed by the tangents and the normals
at the ends of the focal chords of parabola y 2 = 4ax is _____.
Options:
(a) 2ax = y 2 – 2a 2
(b) y = 2a ( x – a )
2
(c) y = 4a ( x – a )
2
(d) y = 4a ( x + a )
2
x2 y 2
Question 6: Let P be a variable point on the ellipse + = 1 with foci F1 and F2 .If A is
10 1
the area of the triangle PF1F2 , then the maximum value of A is _____.
Options:
(a) 3
(b) 4
(c) 5
(d) 6
Question 8: If three parabolas touch all the three lines x = 0 , y = 0 and x + y = 2 , then the
maximum area of the triangle formed by joining their foci is _____.
Options:
(a) 3
(b) 6
3 3
(c)
4
3 3
(d)
2
Question 10: A ( 0, 2) , B and C are three points on the parabola y = x + 4 and such that
2
CBA = . The range of the ordinate of C is _____.
2
Options:
(a) ( −,0 4, )
(b) ( −,0) ( 4, )
(c) 0, 4
(d) ( −,0) 4, )
Question 11: Two congruent circles of the largest possible radii having the following
properties.
(i) They intersect each other orthogonally.
(ii) They touch both the curves 4 ( y + 2) = x and 4 ( 2 – y ) = x in the region
2 2
x −2 2, 2 2 .
Then, the radii of these circles are each equal to _____.
Options:
(a) 2
(b) 3
1
(c)
3
3
(d)
2
Question 12: AB is a chord of a parabola with vertex A. The axis of the parabola is inclined
at angle of 30o with the X axis. BC is drawn perpendicular to AB, meeting the axis of the
parabola at C. If the length of the perpendicular drawn from the focus to the directrix is 8
units, then the projection of BC on the axis of parabola is _____ units long.
Options:
(a) 8
(b) 16
(c) 24
(d) 32
Question 13: The locus of the focus of an ellipse with length of major axis 2a and minor
axis 2b , where a b , which touches the X axis, is _____.
Options:
(a) ( xy 2 – b 2 x ) + ( y 2 – b 2 ) = 4 ( a 2 – b 2 ) y 2
2 2
(b) ( xy 2 + b 2 x ) + ( y 2 – b 2 ) y 2 = 4 ( a 2 – b 2 ) y 4
2 2
(c) ( xy 2 + b 2 x ) – ( y 2 – b 2 ) = 4 ( a 2 – b 2 ) y 2
2 2
(d) ( xy 2 + b 2 x ) + ( y 2 + b 2 ) = 4 ( a 2 – b 2 ) y 2
2 2
Question 14: The locus of a point P moving in the XY plane, such that the ratio of its
distance from S(1, 2) and line x + y = 3 is equal to k , is _____.
Options:
(a) a hyperbola if k 1
(b) a pair of straight line for k 0
(c) an ellipse if k 1
(d) a parabola if k = 1
Question 15: The equation of the transverse axis of a hyperbola which passes through ( 2, 4 )
and whose asymptotes are given by the equation ( x − y )( x + y + 1) = 0 is _____.
Options:
(a) x + y = 0
1
(b) y = −
2
1
(c) x = −
2
(d) none of these
Question 17: If the variable line y = kx + 2h is a tangent to the ellipse 2 x + 3 y = 6 , then the
2 2
x2 y 2
Question 18: Consider an ellipse E + − 1 = 0 . Suppose that C is any circle concentric
16 4
with E. Let A be a point on E and let B be a point on C, such that AB is tangential to both E
and C.
The maximum length of AB is _____.
Options:
(a) 2
(b) 4
(c) 2 2
(d) 4 2
RELATED QUESTION LINK:
https://drive.google.com/file/d/1h7l4-zrOXQE5rgp-m0p4JTbuL8hiO2dY/view?usp=sharing
x2 y 2
Question 19: Consider an ellipse E + − 1 = 0 . Suppose that C is any circle concentric
16 4
with E. Let A be a point on E and let B be a point on C, such that AB is tangential to both E
and C.
The slope of the tangent AB, when the length of AB is maximum is _____.
Options:
(a) 2
1
(b)
2
3
(c)
2
2
(d)
3
x2 y 2
Question 20: Consider an ellipse E + − 1 = 0 . Suppose that C is any circle concentric
16 4
with E. Let A be a point on E and let B be a point on C, such that AB is tangential to both E
and C.
The radius of circle C, when length of AB is maximum, is _____.
Options:
(a) 4 2
(b) 3 2
(c) 2 2
(d) 4
Question 21: A conic passes through the point ( 2, 4 ) and is such that the segment of any of
its tangents at any point contained between the coordinate axes is bisected at the point of
tangency.
Its eccentricity is _____.
Options:
(a) 2
(b) 2
(c) 3
3
(d)
2
Question 22: A conic passes through the point ( 2, 4 ) and is such that the segment of any of
its tangents at any point contained between the coordinate axes is bisected at the point of
tangency.
The foci of the conic are _____.
Options:
( ) (
(a) 2 2, 0 and −2 2, 0 )
(b) ( 2 ) (
2, 2 2 and −2 2, − 2 2 )
(c) ( 4, 4 ) and ( −4, − 4)
( ) (
(d) 4 2, 4 2 and −4 2, − 4 2 )
RELATED QUESTION LINK:
https://drive.google.com/file/d/1788z-ECXtKj8KLbckFb7jYxfK2ORLD6z/view?usp=sharing
Question 23: A conic passes through the point ( 2, 4 ) and is such that the segment of any of
its tangents at any point contained between the coordinate axes is bisected at the point of
tangency.
The equation of its directrices are _____.
Options:
(a) x + y = 8
(b) x + y = 4
(c) x + y = 4 2
(d) none of these
x2 y 2
Question 24: Let S, S be the foci of the ellipse + = 1 whose eccentricity is e. P is a
a 2 b2
variable point on the ellipse. Consider the locus of the incentre of the PSS .
The locus of the incentre is _____.
Options:
(a) an ellipse
(b) a hyperbola
(c) a parabola
(d) a circle
x2 y 2
Question 25: Let S, S be the foci of the ellipse + = 1 whose eccentricity is e. P is a
a 2 b2
variable point on the ellipse. Consider the locus of the incentre of the PSS .
The eccentricity of the locus of P is _____.
Options:
2e
(a)
1− e
2e
(b)
1+ e
(c) 1
(d) none of these
x2 y 2
Question 26: Let S, S be the foci of the ellipse 2 + 2 = 1 whose eccentricity is e. P is a
a b
variable point on the ellipse. Consider the locus of the incentre of the PSS .
The maximum area of the rectangle inscribed in the locus is _____.
Options:
2abe2
(a)
1+ e
2abe
(b)
1− e
abe
(c)
1+ e
(d) none of these
Question 27: If Sk has minimum possible radius equal to that of S1 and Sm , distance
between whose centres is a PQ , then a2 is equal to _____.
Options:
(a) 3
(b) 4
(c) 2
(d) 9
Question 28: An ellipse whose major axis is parallel to X –axis such that the segments of the
focal chords are 1 and 3 units. The lines a x + b y + c = 0 are the chords of the ellipse such that
a, b, c are in A.P. and bisected by the point at which they intersect. The equation of its
auxiliary circle is x 2 + y 2 + 2 x + 2 y − 2 − 1 = 0 then _____.
Equation of the auxiliary circle is
Options:
(a) x 2 + y 2 − 2 x + 4 y + 1 = 0
(b) x 2 + y 2 + 2 x + 2 y − 3 = 0
(c) x2 + y 2 + 2 x + 4 y + 1 = 0
(d) x2 + y 2 − 4 x + 2 y − 3 = 0
Question 29: Consider a parabola (P) having focus at F (1, 2 ) and touching both the
coordinate axes. Equation of directrix of parabola p is _____.
Options:
(a) y + x = 0
(b) y + 2x = 0
(c) y + 3x = 0
(d) y + 4x = 0
Question 30: Consider a parabola (P) having focus at F (1, 2 ) and touching both the
coordinate axes. From point R on axis of parabola P, three real and distinct normals are
drawn to the parabola, then coordinate of R will be _____.
Options:
12
(a) ( 2 − 3, ) /
5
12
(b) ( 2 − 3, ) / =
5
12
(c) ( 2 − 3, ) / 0
5
(d) ( 2 − 3, ) /
Question 31: A straight line L is drawn through the origin and parallel to the tangent to the
curve f ( x, y ) = 0 at an arbitrary point M on the curve. P is the point of intersection of the
line L and the straight line parallel to the Y–axis and passing through the point M. If
f ( x, y ) y − log b x then the locus of P is a _____.
Options:
(a) Straight line
(b) Parabola
(c) Circle
(d) Central conic
Question 33: A straight line L is drawn through the origin and parallel to the tangent to the
curve f ( x, y ) = 0 at an arbitrary point M on the curve. P is the point of intersection of the
line L and the straight line parallel to the Y–axis and passing through the point M. If
a + a2 − x2
f ( x, y ) y − a 2 − x 2 + a ln then the locus of P is a _____.
x
Options:
(a) Straight line
(b) Parabola
(c) Circle
(d) Central conic
Question 34: From a point P, common tangents are drawn to the ellipse x 2 + 4 y 2 = 8 and
parabola y 2 = 4 x . The equation of the common tangents to the ellipse and the parabola are
_____.
Options:
(a) x − 3 = 2 y
(b) x + 4 = 2 y
(c) x − 4 = 2 y
(d) x + 3 = 2 y
MCQ
Question 35: A circle externally touches the two circles x 2 + y 2 = 1 and x 2 + y 2 = 4 x . The
locus of the centre of the circle is a conic C and e is its eccentricity. Then, _____.
Options:
(a) C is an ellipse
(b) C is a hyperbola
(c) e = 2
(d) e2 = 2
Question 37: A hyperbola has a focus at origin, its eccentricity is 2 and the corresponding
directrix is x + y + 1 = 0 . The equation of its asymptotes is/are _____.
Options:
(a) x + 1 = 0
(b) x − 1 = 0
(c) y + 1 = 0
(d) y − 1 = 0
Question 39: Let A, B and C be three distinct points on y 2 = 8 x such that the normals at
these points are concurrent at P. The slope of AB is 2 and the abscissa of the centroid of
4
ABC is . Which of the following is (are) correct?
3
Options:
(a) area of ABC is 8 square units
(b) coordinates of P are (6,0)
(c) angle between normals are 45°, 45°, 90°
(d) angle between normals are 30°, 30°, 60°
Question 40: A hyperbola centred at C has one focus at P ( 6, 8) . If its directrices are
3x + 4 y + 10 = 0 and 3x + 4 y –10 = 0 , then _____.
Options:
(a) CP = 10
(b) eccentricity = 5
(c) CP = 8
5
(d) eccentricity =
2
Question 41: Consider the statement regarding a conic : “If PSQ be a focal chord, and X the
foot of the corresponding directrix, such that XP and XQ are equally inclined to the axis of a
conic”. The conics which always satisfy this property is/are _____.
Options:
(a) Parabola
(b) Ellipse
(c) Hyperbola
(d) Rectangular Hyperbola
Question 42: Let L be the point ( t , 2) and M be a point on the y axis such that LM has slope
− t . Then the locus of the midpoint of LM. as t varies over all real values, is a parabola,
whose.
Options:
(a) Vertex is ( 0, 2 )
(b) Latus – rectum is of length 2
17
(c) Focus is 0,
8
(d) Directrix is 8 y −15 = 0
x2 y2 x2 y2
Question 44: Two ellipses + = 1 and + =10
cos sin
2 2
sin cos
2 2
4
intersect at four points P,Q, R, S then which of the following statement(s) is /are true ?
Options:
(a) PQRS is a square with length of the side sin 2
sin 2
(b) PQRS lie on a circle whose centre is origin and with radius
2
(c) eccentricity of the two given ellipses are same
x2 y2
(d) there are two points on + = 1 whose reflection in y = x lie on the same
sin 2 cos 2
ellipse
INTEGER
x2 y 2
Question 45: The number of points on the hyperbola − = 1 from where mutually
a 2 b2
perpendicular tangents can be drawn to circle x 2 + y 2 = a 2 is _____.
Question 46: If p is the length of the perpendicular from a focus upon the tangent at any
x2 y 2 2a b 2
point P on the ellipse 2 + 2 = 1 and r is the distance of P from the focus, then − 2 =
a b r p
_____.
Question 48: If the length of the latus rectum of a standard hyperbola of eccentricity 2 is
3 5 7
equal to the limit of the series 2 + 2 + 2 + ... and r is the radius of the director
1 1 + 2 1 + 22 + 32
2
96
Question 49: Let P, Q be points on the ellipse 16 x 2 + 25 y 2 = 400 , so that PQ =and P, Q
25
lie above the major axis. The circle drawn with PQ as diameter touches the major axis at the
1
positive focus. If m is the slope of PQ, then find the value of .
m
Question 50: The normal chord at a point t on the parabola y 2 = 4ax subtends a right angle
at its vertex. Find the value of t 2 .
( )
P 0, 4 − 13 is a point on the curve C 2 . Let a line through P meet C1 at m number of
points and C 2 at n number of points. If ( m + n ) = 3 , then the number of such straight lines is
_____.
Question 54: From the origin, tangents OA and OB are drawn to the curve
( x – 2) + ( y – 2) = 1. If the line PQ, where P and Q are respectively the midpoints of OA
2 2
and OB, touches the curve ( y + 3) = 4a ( x + 4 ) and the length of latus rectum of the
2
l
parabola is l , then is _____.
7
Question 55: If two distinct chords of a parabola y 2 = 4ax passing through ( a,2a ) are
bisected by the line x + y = 1, and 4a is a natural number, then the maximum length of the
latus–rectum is _____.
Question 56: Area of trapezium whose vertices lie on the parabola y 2 = 4 x and its diagonals
pass through (1, 0) and having length
25 75
unit each, is . Then is _____.
4
Question 57: Coordinates of the vertices B and C are ( 2, 0 ) and (8, 0) respectively. The
B C
vertex A is varying in such a way that 4 tan tan = 1 . If the locus of A is an ellipse then
2 2
the length of its semi major axis is _____.
Question 58: A parabola is drawn through two given points A (1, 0) and B( −1, 0) such that
its directrix always touches the circle x 2 + y 2 = 4. If the maximum possible length of semi
latus–rectum is k then k is (where [.] denotes greatest integer function)
MATRIX
Question 60: Match the following.
Column – I Column – II
(A) If three normals can be drawn to the curve y 2 = x from the point (p) 0
( c, 0) , then c can be _____.
(B) If the sides and the angles of a plane triangle vary in such a way (q) 1
da db dc
that its circumradius remains constant, then + + =
cos A cos B cos C
_____.
(C) If the point ( a, a ) lies between the lines x + y = 6 , then a is (r) 2
_____, where [.] denotes the greatest integer function and |.| denotes
the absolute value function)
(D) The point ( p + 1 , p ) lies inside the region bounded by the (s) 3
circles x 2 + y 2 − 2 x − 15 = 0 and x 2 + y 2 − 2 x − 7 = 0 . The number of
possible values of p is _____, where [.] denotes the greatest integer
function and |.| denotes the absolute value function).
(t) 4
Options:
(a) A → q, r, s, t; B → p; C → p, q, r; D → p
(b) A → q, r, s, t; B → p; C → p, r; D → p
(c) A → q, t; B → p; C → p, q, r; D → p
(d) A → q, r, t; B → p; C → p, q, r; D → p
S (q) 2
n
(b) Sn = r !( n 6 ) then Sn − 7 n is
r =1 7
(where [ x ] denotes integer less than or
equal to x )
(c) Equation of tangent z0 to the circle (r) 3
z
z = r is Re = , then is
z0
(d) Normal drawn at any point of an ellipse (s) 5
x2 y 2
+ = 1 , is tangent to the circle
25 9
x 2 + y 2 = r 2 then maximum value of r is
(t) 5
Options:
(a) a → s; b → s, t; c → p; d → q
(b) a → r; b → s, t; c → p; d → q
(c) a → r; b → s; c → p; d → q
(d) a → r; b → s, t; c → s; d → q
Options:
(a) (a) → (q); (b) → (s); (c) → (s); (d) → (q)
(b) (a) → (s); (b) → (p); (c) → (s); (d) → (q)
(c) (a) → (s); (b) → (s); (c) → (s); (d) → (q)
(d) (a) → (r); (b) → (s); (c) → (s); (d) → (q)
169
Column – I Column – II
(a) Length major axis 24
(p)
5
(b) Length minor axis 16
(q)
5
(c) Length of Latus Rectum 16
(r)
3
(d) Distance between directrices 72
(s)
5
48
(t)
5
Options:
(a) a → r; b → q; c → r; d → s
(b) a → t; b → q; c → r; d → s
(c) a → t; b → s; c → r; d → s
(d) a → t; b → q; c → q; d → s
Question 67:
Statement I : The locus of a point P, with respect to which, the chord of contact of the curve
y 2 = 4ax subtends 90° at origin, is x = −4a .
because
Statement II : If the normal drawn at the point t1 on the curve y 2 = 4ax cuts the parabola
again at t 2 if t1 is real, when t2 2 2 .
Options:
(a) Statement I is True; Statement II is True; Statement II is a correct explanation
for Statement I.
(a) Statement I is True; Statement II is True; Statement II is not a correct explanation
for Statement I.
(c) Statement I is True; Statement II is False.
(d) Statement I is False; Statement II is True.