First Quarter Book Test
Unit 1 – 3
T-1
Objective Type
Time Allowed: 20 Min.Max. Marks: 15
Note: Four possible answer A, B, C and D to each question are given. The choice which you think is correct, fill that circle front of that question with Marker or ink pen in the answer book. Cutting filling two or more circles will result in zero mark in that question.
1.A complex number Z = x + iy is called pure imaginary if
(A) x = 0, y = 0
(B) x ≠ 0, y = 0
(C) x = 0, y ≠ 0
(D) none of these
Answer: C
2.If Z = 1 – i then | Z | =
(A) 0
(B) √2
(C) 2
(D) none of these
Answer: B
3.If Z = x + iy then
(A) x and y both are real numbers
(B) x and y both are imaginary numbers
(C) x is real and y is imaginary
(D) x is imaginary and y is real
Answer: A
4.Im (Z) can be expressed as:
(A) Z + Z2
(B) Z – Z2
(C) Z + Z2i
(D) Z – Z2i
Answer: D
5.Z Z =
(A) Z2
(B) | Z |2
(C) – Z2
(D) None of these
Answer: B
6.For any a and b, which of the following is true?
(A) a2 + b2 ≥ 2ab
(B) a2 + b2 ≤ 2ab
(C) a2 + b2 = 2ab
(D) None of these
Answer: A
7.If (x – 2) (x – 3) = 6, then we can write:
(A) x – 2 = 6
(B) x – 3 = 6
(C) x + 6 = 6
(D) None of these
Answer: D
8.Graph of the function f(x) = x2 + 2x – 3 = (x + 3) (x – 1) is.
Answer: B (upward parabola, roots at –3 and 1)
9.The expression ax2 + bx + c = 0 is a quadratic equation if:
(A) a ≠ 0
(B) b ≠ 0
(C) c ≠ 0
(D) a ≠ 0, b ≠ 0, c ≠ 0
Answer: A
10.Which of the following expression is a quadratic equation in standard form?
(A) 2x2 = 3x + 1
(B) 1x+1 + 1x+2 = 2
(C) x2 + 1x2 = 2
(D) None of these
Answer: A
11.A = x6515 is singular if x =
(A) 0
(B) 1
(C) 2
(D) not possible
Answer: C (15x – 30 = 0 ⇒ x = 2)
12.If A = 44 and B = 25 then BA =
(A) [28]
(B) [ – 12]
(C) [12]
(D) 820820
Answer: A (2×4 + 5×4 = 28)
13.If A is of order m-by-n and B is of order n-by-f then AB is of order:
(A) n-by-n
(B) f-by-m
(C) m-by-f
(D) None of these
Answer: C
14.If A = 2341 and I = 1001 then AI =
(A) 2341
(B) 2001
(C) 3342
(D) none of these
Answer: A
15.A matrix A is called skew symmetric if:
(A) A′ = A
(B) A′ = – A
(C) A′ = 1A
(D) A′ = –1A
Answer: B
Answer Key: 1-C, 2-B, 3-A, 4-D, 5-B, 6-A, 7-D, 8-B, 9-A, 10-A, 11-C, 12-A, 13-C, 14-A, 15-B