Q141.For a complex number z the value of (z 3) (z 3) is equivalent to–
Correct answer: 2/z 3
Q142.If x 1 i 1 1 i
Correct answer: x = 4n
Q143.Let x, y ∈ IR, then x + iy is a non-real complex number if–
Correct answer: y ≠ 0
Q144.Real part of 5 + 2i 3- 4i 1 z = – – 2-5i 4 + 3i i is:
Correct answer: 0
Q145.The value of -6 -6 is:
Correct answer: –6
Q146.If α and β are different complex numbers and |β|=1 then what will be the value of β - 1- β α?
Correct answer: 1
Q147.If z is a complex number, which satisfies z2 +z+1=0. If n is not multiple of 3, then the value of zn +z2n is:
Correct answer: –1
Q148.nth cube root of the unit will be:
Correct answer: Geometric Progression
Q149.If the area of the triangle formed by the vertices z, z+iz and iz of the triangle in the complex plane is 50,m then the value of |z| is:
Correct answer: 10
Q150.If a,b,c,d are real numbers, then a ib c id + is real if:
Correct answer: ad = bc
Q151.The value of 4 4 1 (1 i) 1 i is–
Correct answer: 16
Q152.The locus determined by z 1 2 z 1 + = − where z 1 and z x iy is–
Correct answer: a circle with centre 5,0 3
Q153.If 1, w, w2 are the cube roots of unity then the roots of the equation (x–1)3 + 8 = 0 are –
Correct answer: 2 1,1 2w,1 2w − − −
Q154.If the real part of z 1 z i, where z x iy is 1 then the point (x,y) lies on–
Correct answer: a straight line of gradient one
Q155.The equation zz 3 = where z x iy and z is the conjugale complex of represents–
Correct answer: A circle
Q156.The smallest positive integer n for which the real part of (1+i)n is zero is–
Correct answer: 2
Q157.The complex number z, for which |z+5|2 + |z–5|2 = 75, represents:
Correct answer: a circle
Q158.If ω is a complex cube root of unity then ω100 +ω17 +1 equals:
Correct answer: 0
Q159.For real x, the complex numbers sin x+i cos 2x and cos x–i sin 2x are conjugate to each other for:
Correct answer: no value of x
Q160.If 5 5 3 1 3 1 Z i i 2 2 2 2 = + + − = + + − = + + − = + + − then:
Correct answer: Im (Z) = 0