11. The value of arg(−5i) is:
A. 0◦
B. −90◦
C. 180◦
D. 270◦
12. The value of Arg(−5i) is:
A. 0◦
B. -90◦
C. 180◦
D. 270◦
13. The value of Arg(−5) is:
A. 0◦
B. 90◦
C. 180◦
D. 270◦
14. The equation of a circle with center at origin and radius 2 is:
A. |z| = 2
B. |z| = 4
C. |z| = √ 2
D. None of these
15. Which of the following is not true?
A. arg(z1z2)= arg(z1) + arg(z2)
B. Arg(z1z2)= Arg(z1) + Arg(z2)
C. zz̅= |z|2
D. arg( z1z2 )= arg(z1) – arg(z2)
16. The least value of |z1 + z2| is:
A. ||z1| + |z2||
B. ||z1||z2||
C. ||z1|/|z2||
D. ||z1| − |z2||
17. The inequality ||z1| − |z2|| ≤ |z1 + z2| ≤ |z1| + |z2| is called:
A. Triangle Inequality
B. Minkowski Inequality
C. Cauchy-Schwarz Inequality
D. Holder’s Inequality
18. The principal argument of any complex number can not be:
A. 7π/8
B. 7π/6
C. π/2
D. − π/2
19. If |z| = 2i(1 − i)(2 − 4i)(3 + i), then |z| equals:
A. 20
B. −20
C. 40
D. −40
20. z = a + ib is pure imaginary if and only if:
A. z = −z̅
B. z = z
C. z = −z
D. z = z^−1