Locus of the poles of focal chord of a parabola is from Mathemat

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

281.

The pole of the straight line x + 4y = 4 with respect to the ellipse x2 + 4y2 = 4 is

  • (1, 1)

  • (1, 4)

  • (4, 1)

  • (4, 4)


Advertisement

282.

Locus of the poles of focal chord of a parabola is

  • the axis

  • a focal chord

  • the directrix

  • the tangent at the vertex


C.

the directrix

                       y - 2at1 = 2at2 - 2at1at22 - at12x - at12  t2 + t1 y - 2at1 = 2x - at12        t1 + t2y - 2x =  2at1t2          ...iThis line is passing through a, 0       t1 + t2-2at1 = 2t1 + t2 a - at12                           t1t2 = - 1           ...ii       Let Px1, y1 be the pole of  i  w.r.t. y2 = 4axIts polar is  yy1 = 2a x + x1            ... iiiFrom equation i and iii, we gwet            t1 + t2y1 =1a = 2at1t22ax1From last two relations, we get                   x1 = at1t2               x1 = - a     locus is x = - a


Advertisement
283.

The equation 1r = 18 + 38cosθ represents

  • a parabola

  • an ellipse

  • a hyperbola

  • a rectangular hyperbola


284.

If the circle x2 + y2 + 6x - 2y + k = 0 bisects the circumference of the circle x2 + y2 + 2x - 6y - 15 = 0, then k is equal to:

  • 21

  • - 21

  • 23

  • - 23


Advertisement
285.

If P is a point such that the ratio of the square of the lengths of the tangents from P to the circles x2 + y2 + 2x - 4y - 20 = 0 and x2 + y2 - 4x + 2y - 2y - 44 = 0 is 2 : 3, then the locus of P is a circle with centre :

  • (7, - 8)

  • (- 7, 8)

  • (7, 8)

  • (- 7, - 8)


286.

If 5x - 12y + 10 = 0 and 12y - 5x + 16 = 0 are two tangents to a circle, then the radius of the circle is

  • 1

  • 2

  • 4

  • 6


287.

The eccentricity of the ellipse 9x2 + 5y2 - 18x - 20y - 16 = 0, is:

  • 12

  • 23

  • 32

  • 2


288.

The product of the lengths of perpendiculars drawn from any point on the hyperbola x2 - 2y2 - 2 = O to its asymptotes is

  • 12

  • 23

  • 32

  • 2


Advertisement
289.

The equation of the parabola with focus (0, 0)and directrix x + y = 4 is

  • x2 + y2 - 2xy + 8x +8y -16 = 0

  • x2 + y2 - 2xy + 8x + 8y = 0

  • x2 + y2 + 8x + 8y - 16= 0

  • x2 - y2 + 8x +8y - 16= 0


290.

The number of circles that touch all the three lines x + y - 1 = 0, x - y - 1 = 0 and y + 1 = 0 is

  • 2

  • 3

  • 4

  • 1


Advertisement