MCQs Questions for Class 11 Maths Chapter 5 Complex Numbers and Quadratic Equations
In this 21st century, Multiple Choice Questions (MCQs) play a vital role to prepare for a competitive examination. CBSE board has also brought a major change in its board exam patterns. In most of the competitive examinations, only MCQ Questions are asked.
In future, if you want to prepare for competitive examination, then you should focus on the MCQs questions. Thus, let’s solve these MCQs questions to make our foundation strong.
In this post, you will find 15 MCQs questions for class 11 maths chapter 5 complex numbers and quadratic equations.
MCQs Questions for Class 11 Maths Chapter 5 Complex Numbers and Quadratic Equations
1. The value of
√(-81) is
(a) -9i
(b) 9i
(c) -3i
(d) 3i
Answer: b
2. In a
complex number, z = 4 + i, what is the real part?
(a) 4
(b) i
(c) 1
(d) 4 + i
Answer: b
3. The value of
√(-144) is
(a) 12i
(b) -12i
(c) ±12i
(d) None of these
Answer: a
4. If
(x + 3) + i(y – 2) = 5 + 2i, then find
the values of x and y.
(a) x = 8 and y = 4
(b) x = 2 and y = 4
(c) x = 2 and y = 0
(d) x = 8 and y = 0
Answer: b
5. If z lies on |z| = 1, then 2/z lies on
(a) a circle
(b) an ellipse
(c) a straight line
(d) a parabola
Answer: a
6. If z1 = 2 + 3i
and z2 = 5 + 2i, then find the sum of two complex
numbers.
(a) 4 + 8i
(b) 3 – I
(c) 7 + 5i
(d) 7 – 5i
Answer: c
7. If ω is an imaginary cube root of unity, then
(1 + ω – ω²)7 equals
(a) 128 ω
(b) -128 ω
(c) 128 ω²
(d) -128 ω²
Answer: d
8. -z is _________________ for the complex number
z.
(a) additive inverse
(b) additive identity element
(c) multiplicative identity element
(d) multiplicative inverse
Answer: a
9. The least value of n for which {(1 + i)/(1 –
i)}n is real, is
(a) 1
(b) 2
(c) 3
(d) 4
Answer: b
10. 1/z is _________________ for complex number z.
(a) additive inverse
(b) additive identity element
(c) multiplicative identity element
(d) multiplicative inverse
Answer: d
11. The value of i-999 is
(a) 1
(b) -1
(c) i
(d) -i
Answer: c
12. If z1 = 8 + 5i
and z2 = 3 + 6i, then find the value of z1 – z2.
(a) -5 + i
(b) 5 – i
(c) 5 + i
(d) 5 – 5i
Answer: b
13. The complex numbers sin x + i cos 2x and sin x – i cos 2x are
conjugate to each other for
(a) x = nπ
(b) x = 0
(c) x = (n + 1/2) π
(d) no value of x
Answer: d
14. In the complex number, z = 5 + 2i, what
is the imaginary part?
(a) 5
(b) 2i
(c) 5 + 2
(d) 5 + 2i
Answer: b
15. The value of x and y if (3y – 2) + i(7 – 2x) =
0 is
(a) x = 7/2, y = 2/3
(b) x = 2/7, y = 2/3
(c) x = 7/2, y = 3/2
(d) x = 2/7, y = 3/2
Answer: a