MCQs: Math 11 NBF

Chose the correct option.

i. Every real number is also a number.

• (a) natural
• (b) integer
• (c) complex
• (d) rational
  See Answer

  (c): complex

ii. Every complex number has $\operatorname{part}(\mathrm{s})$.

• (a) one
• (b) two
• (c) three
• (d) no
  See Answer

  (b): two

iii. Magnitude of a complex number $z$ is the distance of $z$ from

• (a) $(0,0)$
• (b)$(1,0)$
• (c) $(0,1)$
• (d) $(1,1)$
  See Answer

  (a): $(0,0)$

iv. If $z$ is a complex number then its mirror image is

• (a) $|z|$
• (b) $1 / z$
• (c) $-z$
• (d) $\bar{z}$
  See Answer

  (d): $\bar{z}$

v. In complex plane imaginary part is drawn along

• (a) $x$-axis
• (b) $y$-axis
• (c) origin
• (d) $x y$-plane
  See Answer

  (b): $y$-axis

vi. If $z_{1}=3+2 i$ and $z_{2}=5+6 i$ then

• (a) $z_{1}>z_{2}$
• (b) $z_{1}<z_{2}$
• (c) $\overline{z_{1}}=\overline{z_{2}}$
• (d) $\overline{z_{1}}=-\overline{z_{2}}$
  See Answer

  (d): $\overline{z_{1}}=-\overline{z_{2}}$

vii. Diagram representing a complex number is called diagram.

• (a) vector
• (b) Venn
• (c) argand
• (d) ordered pair
  See Answer

  (c): argand

viii. If $\mathrm{z}=3+4 i$ then $\mathrm{z}^{-1}$ is

• (a) $\left(\frac{1}{3}, \frac{1}{4}\right)$
• (b) $\left(-\frac{1}{3},-\frac{1}{4}\right)$
• (c) $\left(\frac{3}{25}, \frac{-4}{25}\right)$
• (d) $\left(\frac{3}{25}, \frac{-4}{25}\right)$
  See Answer

  (d): $\left(\frac{3}{25}, \frac{-4}{25}\right)$

ix. The value of $(\sqrt{-25})(\sqrt{-4})$ is

• (a) $10$
• (b) $-10$
• (c) $10 i$
• (d) $-10 i$
  See Answer

  (b): $-10$

x. If $\left(\frac{1+i}{1-i}\right)^{n}=1$ then least positive value of $n$ is

• (a) $1$
• (b) $2$
• (c) $3$
• (d) $4$
  See Answer

  (b): $2$