CBSE  /  Class 11  /  Maths  /  Complex Numbers and Quadratic Equations

  • 1. 
    The value of √(-16) is

  • -4i
  • 4i
  • -2i
  • 2i

  • 2. 
    The value of √(-144) is

  • 12i
  • -12i
  • ±12i
  • None of these

  • 3. 
    The value of √(-25) + 3√(-4) + 2√(-9) is

  • 13i
  • -13i
  • 17i
  • -17i

  • 4. 
    if z lies on |z| = 1, then 2/z lies on

  • a circle
  • an ellipse
  • a straight line
  • a parabola

  • 5. 
    If ω is an imaginary cube root of unity, then (1 + ω – ω²)7 equals

  • 128 ω
  • -128 ω
  • 128 ω²
  • -128 ω²

  • 6. 
    The least value of n for which {(1 + i)/(1 – i)}n is real, is

  • 1
  • 2
  • 3
  • 4

  • 7. 
    Let z be a complex number such that |z| = 4 and arg(z) = 5π/6, then z =

  • -2√3 + 2i
  • 2√3 + 2i
  • 2√3 – 2i
  • -√3 + i

  • 8. 
    The value of i-999 is

  • 1
  • -1
  • i
  • -i

  • 9. 
    Let z1 and z2 be two roots of the equation z² + az + b = 0, z being complex. Further assume that the origin, z1 and z1 form an equilateral triangle. Then

  • a² = b
  • a² = 2b
  • a² = 3b
  • a² = 4b

  • 10. 
    The complex numbers sin x + i cos 2x are conjugate to each other for

  • x = nπ
  • x = 0
  • x = (n + 1/2) π
  • no value of x
Report Question
warning
Practice More On Complex Numbers and Quadratic Equations
Quiz 1 Quiz 2
access_time
  Time