The eccentricity of an ellipse, with its centre at the origin, i

Subject

Mathematics

Class

JEE Class 12

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

31.

The intercept on the line y = x by the circle x2 +y2 -2x = 0 is AB. Equation of the circle on AB as a diameter is

  • x2 +y2 -x-y =0

  • x2 -y2 -x-y =0

  • x2 +y2 +x-y =0

  • x2 +y2 +x-y =0

272 Views

32.

If a ≠ 0 and the line 2bx + 3cy + 4d = 0 passes through the points of intersection of the parabolas y2+ 4ax = and  x2+ 4ay = , then

  • d2 + (2b+3c)2 = 0

  • d2 +(3d+2c2) = 0

  • d2 + (2b-3c)2 = 0

  • d2 + (2b-3c)2 = 0

868 Views

Advertisement

33.

The eccentricity of an ellipse, with its centre at the origin, is 1 /2 . If one of the directrices is x = 4, then the equation of the ellipse is

  • 3x2 +4y2 = 1

  • 3x2+ 4y2 = 12

  • 4x2 +3y2 = 12

  • 4x2 +3y2 = 12


B.

3x2+ 4y2 = 12

Since the directrix is x = 4 then ellipse is parallel to X-axis.
⇒ a/e = 4
⇒ a = 4e = 4 x (1/2)
⇒ a = 2
Also we know that
b2 =a2 (1-e2)
b2 = 4(1-1/4) = 4 x 3/4
b2 = 3
therefore equation of ellipse is
straight x squared over 4 space plus straight y squared over 3 space equals space 1
3 straight x squared space plus space 4 straight y squared space equals space 12

311 Views

Advertisement
34.

Consider the following statements:
(a) Mode can be computed from histogram
(b) Median is not independent of change of scale
(c) Variance is independent of the change of origin and scale. Which of these is/are correct?

  • only (a)

  • only (b)

  • only (a) and (b)

  • only (a) and (b)

141 Views

Advertisement
35.

In a series of 2n observations, half of them equal a and remaining half equal –a. If the standard deviation of the observations is 2, then |a| equals 

  • 1/n

  • square root of 2
  • 2

  • 2

502 Views

36.

The probability that A speaks truth is 4/ 5 , while this probability for B is 3/ 4 . The probability that they contradict each other when asked to speak on a fact is

  • 3/20

  • 1/20

  • 7/20

  • 7/20

141 Views

37.

Suppose four distinct positive numbers a1, a2, a3, a4 are in G.P. Let b1 = a1, b2 = b1 + a2, b3 = b2 + a3 and b4 = b3 + a4.
Statement-I: The numbers b1, b2, b3, b4are neither in A.P. nor in G.P. Statement-II: The numbers b1, b2, b3, b4 are in H.P.

  • Both statement-I and statement-II are true but statement-II is not the correct explanation of statement-I

  • Both statement-I and statement-II are true, and statement-II is correct explanation of Statement-I

  • Statement-I is true but statement-II is false.

  • Statement-I is true but statement-II is false.

233 Views

38.

If x = ω – ω2 – 2. Then the value of (x4 + 3x3 + 2x2 – 11x – 6) is

  • 0

  • -1

  • 1

  • 1

186 Views

Advertisement
39.

Maximum sum of coefficient in the expansion of (1 – x sinθ + x2 )n is

  • 1

  • 2n

  • 3n

  • 3n

126 Views

40.

Let R = {(1, 3), (4, 2), (2, 4), (2, 3), (3, 1)} be a relation on the set A = {1, 2, 3, 4}. The relation R is

  • a function

  • reflexive

  • not symmetric

  • not symmetric

149 Views

Advertisement