ECAT — Engineering College Admission Test (UET)

ECAT Mathematics — Conic Sections (Set 4)

Take the ECAT Mathematics — Conic Sections (Set 4): 30 multiple-choice questions (40 minutes) with instant scoring and a full answer review. Covers 30…

What this test covers

Sample questions with answers

The first 5 questions of this test, with the correct answer and explanation.

  1. Q1. The radius of the circle x² + y² − 6x + 8y = 0 is

    • A. 25
    • B. 10
    • C. √5
    • D. 5 ✓

    Answer: D. 5

    Explanation: Completing squares: (x − 3)² + (y + 4)² = 25, so the radius is 5 (the centre is (3, −4)).

  2. Q2. The focus of the parabola x² = 20y is

    • A. (0, 10)
    • B. (0, 5) ✓
    • C. (0, 20)
    • D. (5, 0)

    Answer: B. (0, 5)

    Explanation: x² = 4ay with 4a = 20 gives a = 5, so the focus is (0, 5).

  3. Q3. An ellipse has semi-major axis 10 and semi-minor axis 6. Its eccentricity is

    • A. 4/5 ✓
    • B. 16/25
    • C. 8/5
    • D. 3/5

    Answer: A. 4/5

    Explanation: e = √(1 − b²/a²) = √(1 − 36/100) = √(64/100) = 4/5.

  4. Q4. The foci of the conic 5y² − 4x² = 20 are

    • A. (±3, 0)
    • B. (0, ±1)
    • C. (0, ±√5)
    • D. (0, ±3) ✓

    Answer: D. (0, ±3)

    Explanation: Dividing by 20: y²/4 − x²/5 = 1. The y² term is positive, so the transverse axis is vertical, with c² = 4 + 5 = 9. The foci are (0, ±3).

  5. Q5. The length of the latus rectum of the parabola y² = 8x is

    • A. 8 ✓
    • B. 16
    • C. 4
    • D. 2

    Answer: A. 8

    Explanation: For y² = 4ax the latus rectum is 4a. Here 4a = 8.

The other 25 questions

Take the timed test (free, no sign-up) to see your score and the answer and explanation for every question.

  1. Q6. The tangent to the circle x² + y² = 25 at the point (3, 4) is

    • A. 3x + 4y = 25
    • B. 3x − 4y = 25
    • C. 3x + 4y = 5
    • D. 4x + 3y = 25
  2. Q7. The circle through (0, 0), (2, 0) and (0, 4) has radius

    • A. √5
    • B. √3
    • C. 5
    • D. 2√5
  3. Q8. The directrix of the parabola x² = −16y is

    • A. x = 4
    • B. y = −4
    • C. y = 4
    • D. y = 16
  4. Q9. The length of the latus rectum of the ellipse 9x² + 16y² = 144 is

    • A. 18
    • B. 9/2
    • C. 9
    • D. 3
  5. Q10. The eccentricity of the hyperbola 25x² − 16y² = 400 is

    • A. √41/4
    • B. √41/5
    • C. 9/4
    • D. 5/4
  6. Q11. The line y = 2x + c is tangent to the parabola y² = 8x when c equals

    • A. 2
    • B. 1
    • C. 4
    • D. 1/2
  7. Q12. The line y = x + c touches the circle x² + y² = 8 for a positive c equal to

    • A. 2√2
    • B. 4
    • C. 8
    • D. √8/2
  8. Q13. The distance between the foci of the ellipse x²/49 + y²/24 = 1 is

    • A. 5
    • B. 14
    • C. 2√73
    • D. 10
  9. Q14. The equation x² + 2xy + y² + 3x + 2 = 0 represents

    • A. an ellipse
    • B. a hyperbola
    • C. a parabola
    • D. a circle
  10. Q15. The circle x² + y² − 6x − 4y + k = 0 touches the x-axis when k equals

    • A. −9
    • B. 9
    • C. 4
    • D. 13
  11. Q16. The circle on the line segment joining (1, 2) and (5, 6) as diameter has equation

    • A. x² + y² + 6x + 8y + 17 = 0
    • B. x² + y² − 6x − 8y + 7 = 0
    • C. x² + y² − 6x − 8y + 17 = 0
    • D. x² + y² − 3x − 4y + 17 = 0
  12. Q17. The parabola with vertex at the origin and focus (0, −2) has equation

    • A. x² = 8y
    • B. x² = −8y
    • C. y² = −8x
    • D. x² = −2y
  13. Q18. The ellipse with foci (±3, 0) and major axis of length 10 has equation

    • A. x²/100 + y²/91 = 1
    • B. x²/25 + y²/9 = 1
    • C. x²/16 + y²/25 = 1
    • D. x²/25 + y²/16 = 1
  14. Q19. For the ellipse 4x² + 9y² − 16x + 18y − 11 = 0, the foci are

    • A. (±√5, 0)
    • B. (−2 ± √5, 1)
    • C. (2 ± √5, −1)
    • D. (2, −1 ± √5)
  15. Q20. The length of the tangent from (5, 4) to the circle x² + y² − 2x − 4y − 4 = 0 is

    • A. √15
    • B. √11
    • C. 3
    • D. 11
  16. Q21. The length of the common chord of the circles x² + y² = 25 and (x − 6)² + y² = 25 is

    • A. 4
    • B. 6
    • C. 8
    • D. 10
  17. Q22. The tangent to the parabola y² = 16x at the point (1, 4) is

    • A. 4x − y = 0
    • B. 2x + y − 6 = 0
    • C. x − 2y + 7 = 0
    • D. 2x − y + 2 = 0
  18. Q23. The locus of a point P such that |PF₁ − PF₂| = 6, where F₁ = (5, 0) and F₂ = (−5, 0), is

    • A. x²/25 − y²/9 = 1
    • B. x²/16 − y²/9 = 1
    • C. x²/9 + y²/16 = 1
    • D. x²/9 − y²/16 = 1
  19. Q24. The focal chord of y² = 4x passing through the point (4, 4) has length

    • A. 25/4
    • B. 25/2
    • C. 5
    • D. 9
  20. Q25. The line y = x + k is tangent to the ellipse x²/9 + y²/4 = 1 for a positive k equal to

    • A. √13
    • B. √5
    • C. 5
    • D. 13
  21. Q26. A hyperbola x²/a² − y²/b² = 1 has asymptotes y = ±x/2. Its eccentricity is

    • A. √5
    • B. 5/4
    • C. √3/2
    • D. √5/2
  22. Q27. The circles x² + y² = 1 and (x − 3)² + y² = 4 have how many common tangents?

    • A. 4
    • B. 2
    • C. 1
    • D. 3
  23. Q28. A parabola with vertex at the origin and the x-axis as axis passes through (3, 6). Its latus rectum has length

    • A. 6
    • B. 36
    • C. 24
    • D. 12
  24. Q29. An ellipse has its latus rectum equal to the distance between its foci. Its eccentricity is

    • A. 1/√2
    • B. (√5 − 1)/2
    • C. 1/2
    • D. (√5 + 1)/2
  25. Q30. Tangents are drawn from (5, 0) to the circle x² + y² = 9. The area of the quadrilateral formed by the centre, the external point and the two points of contact is

    • A. 12
    • B. 15
    • C. 24
    • D. 6