MCQs for Class 11 Maths Chapter 5, covering Complex Numbers and Quadratic Equations, are available here to help students prepare for their exams. These multiple-choice questions include correct answers with explanations. They cover key concepts from the CBSE syllabus, focusing on topics important for exams.
By practicing these MCQs, students can strengthen their understanding of complex numbers and improve their ability to solve quadratic equations with complex roots.
MCQs for Class 11 Maths Chapter 5 Complex Numbers and Quadratic Equations with Answers
What is the imaginary unit denoted by?
- a) i
- b) j
- c) k
- d) x
Answer: a) i
- What is
i2equal to?- a) 1
- b) -1
- c) 0
- d) i
Answer: b) -1
What is the conjugate of the complex number z = 3 + 4i?
- a) 3 – 4i
- b) 3 + 4i
- c) -3 – 4i
- d) -3 + 4i
Answer: a) 3 – 4i
What is the modulus of z = 3 + 4i?
- a) 5
- b) 7
- c) 25
- d) 1
Answer: a) 5
What is (3 + 4i) + (5 - 2i)?
- a) 8 + 2i
- b) 8 – 6i
- c) 15 + 8i
- d) 8 + 6i
Answer: a) 8 + 2i
If z1 = 2 + 3i and z2 = 1 - 4i, what is z1 - z2?
- a) 1 + 7i
- b) 3 + 7i
- c) 1 – 7i
- d) 3 – 7i
Answer: d) 3 – 7i
What is the principal argument of z = -1 + i?
- a) π/4
- b) 3π/4
- c) -π/4
- d) π
Answer: b) 3π/4
What is the polar form of z = 1 + i?
- a) √2(cos π/4 + i sin π/4)
- b) 2(cos π/4 + i sin π/4)
- c) √2(cos π/2 + i sin π/2)
- d) 1 + i
Answer: a) √2(cos π/4 + i sin π/4)
If z = 2 + 3i, what is |z|2?
- a) 13
- b) 25
- c) 29
- d) 9
Answer: a) 13
Solve the equation x2 + 1 = 0.
- a) ±i
- b) ±1
- c) i
- d) -i
Answer: a) ±i
What is (3 + 4i) + (5 - 2i)?
- a) 8 + 2i
- b) 8 – 6i
- c) 15 + 8i
- d) 8 + 6i
Answer: a) 8 + 2i
If z1 = 2 + 3i and z2 = 1 - 4i, what is z1 - z2?
- a) 1 + 7i
- b) 3 + 7i
- c) 1 – 7i
- d) 3 – 7i
Answer: d) 3 – 7i
What is the principal argument of z = -1 + i?
- a) π/4
- b) 3π/4
- c) -π/4
- d) π
Answer: b) 3π/4
What is the polar form of z = 1 + i?
- a) √2(cos π/4 + i sin π/4)
- b) 2(cos π/4 + i sin π/4)
- c) √2(cos π/2 + i sin π/2)
- d) 1 + i
Answer: a) √2(cos π/4 + i sin π/4)
If z = 2 + 3i, what is |z|2?
- a) 13
- b) 25
- c) 29
- d) 9
Answer: a) 13
Solve the equation x2 + 1 = 0.
- a) ±i
- b) ±1
- c) i
- d) -i
Answer: a) ±i
What is the sum of the roots of x2 - 3x + 2 = 0?
- a) 3
- b) -3
- c) 2
- d) 1
Answer: a) 3
What is the product of the roots of x2 + 2x + 1 = 0?
- a) 1
- b) 2
- c) 0
- d) -1
Answer: d) -1
The complex number z = a + bi lies in which quadrant if a > 0, b > 0?
- a) First
- b) Second
- c) Third
- d) Fourth
Answer: a) First
If z = 4 - 3i, what is &overline;z ⋅ z?
- a) 25
- b) 16
- c) 9
- d) 0
Answer: a) 25
What is the cube root of unity, ω, such that ω3 = 1?
- a) 1
- b) -1
- c) (-1 + √3i)/2
- d) √3i
Answer: c) (-1 + √3i)/2
Solve x2 + 4x + 5 = 0 for complex roots.
- a) -2 ± i
- b) -2 ± 3i
- c) 2 ± i
- d) 2 ± 3i
Answer: a) -2 ± i
What is the polar form of z = -2i?
- a) 2(cos 3π/2 + i sin 3π/2)
- b) 2(cos π + i sin π)
- c) 2(cos 0 + i sin 0)
- d) 2(cos π/2 + i sin π/2)
Answer: a) 2(cos 3π/2 + i sin 3π/2)
The modulus of z = -5 + 12i is:
- a) 13
- b) 17
- c) 25
- d) 0
Answer: a) 13
What is i4?
- a) 1
- b) -1
- c) i
- d) 0
Answer: a) 1
For the quadratic equation x2 + 3x + 2 = 0, the roots are:
- a) -1 and -2
- b) 1 and 2
- c) 3 and -2
- d) 2 and -1
Answer: a) -1 and -2
