f(z) = u(x, y) + iv(x, y) is an analytic function or complex variable z = x + iy where
i = − 1 , u(x, y) = 2xy, then v(x, y) may be expressed as
A. -x2 + y2 + constant
B. x2 - y2 + constant
C. x2 + y2 + constant
D. -(x2 + y2 ) + constant
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The product of complex numbers (3 - 2i) and (3 + i4) results in
A. 1 + 6i
B. 9 - 8i
C. 9 + 8i
D. 17 + 6i
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If a complex number
z = 2 3 + i 2 1 then z
4 is
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If C is a circle of radius r with centre z0 , in the complex z-plane and if n is a non-zero integer, then ∮ ( z − z 0 ) n + 1 dz equals
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Contour C in the adjoining figure is described by x
2 + y
2 = 16. The value
c ∮ 0.5 z − 1.5 j z 2 + 8 dz is (Note:
j = − 1 )
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The value of ∮ z sin z dz, where the counter of integration is a simple closed curve around the origin, is
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z = − 5 + i 2 − 3 j can be expressed as
A. -0.5 - 0.5i
B. -0.5 + 0.5i
C. 0.5 - 0.5i
D. 0.5 + 0.5i
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Consider the following complex function f ( z ) = ( z − 1 ) ( z + 2 ) 2 9
Which of the following is one of the residues of the above function?
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The value of c ∮ z 4 − 1 z 2 dz using Cauchy's integral formula, around circle |z + 1| = 1 where z = x + iy is
A. 2πi
B. − π 2 i
C. − 3 π 2 i
D. π2 i
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The modulus of the complex number ( 1 − 2 i 3 + 4 i ) is
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If f(z) = (x
2 + ay
2 ) + i bxy is a complex analytic function of z = x + iy, where
i = − 1 , then
A. a = -1, b = -1
B. a = -1, b = 2
C. a = 1, b = 2
D. a = 2, b = 2
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An analytic function of a complex variable z = x + iy is expressed as f(z) = u(x, y) + iv(x, y) where
i = − 1 . If u = xy, the expression for v should be
A. 2 ( x + y ) 2 + k
B. 2 x 2 − y 2 + k
C. 2 y 2 − x 2 + k
D. 2 ( x − y ) 2 + k
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F(z) is a function of the complex variable z = x + iy given by F(z) = iz + k Re(z) + iI m(z) For what value of k will F(z) satisfy the Cauchy-Riemann equations
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The value of the integral − ∞ ∫ ∞ x 2 + 2 x + 2 sin x dx evaluated using contour integration and the residue theorem is
A. e − π sin ( 1 )
B. e − π cos ( 1 )
C. e sin ( 1 )
D. e cos ( 1 )
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Consider the line integral
I = ∫ c ( x 2 + i y 2 ) dz, where z = x + iy. The line c is shown in the figure below
The value of
I is
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The product of a complex number z = x + iy and its complex conjugate z is
A. x2
B. y2
C. x2 - y2
D. x2 + y2
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If z = x + jy, where x and y are real, the value of |ejz | is
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The value of ∮ z 2 1 dz, where the contour is the unit circle traversed clockwise, is
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Evaluate ∮ c ( z − 1 ) 3 ⋅ ( z − 3 ) 1 dz where c is the rectangular region defined by x = 0, x = 4, y = -1 and y = 1
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If f(z) = C0 + C1 z-1 , then unit circle ∮ z 1 + f ( z ) dz is given by
A. 2πC1
B. 2π(1 + C0 )
C. 2πjC1
D. 2πj(1 + C0 )
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