MCQs: Math 11 NBF

<lead>Multiple Choice Questions (MCQs) of the Model Textbook of Mathematics for Class XI is published by National Book Foundation (NBF), Islamabad, Pakistan. NBF can be considered as Federal Textbook Board Islamabad. </lead>

Chose the correct option.

i. Every real number is also a number.

• (a) natural
• (b) integer
• (c) complex
• (d) rational
  <btn type=“link” collapse=“a1”>See Answer</btn>

  (c): complex

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

• (a) one
• (b) two
• (c) three
• (d) no
  <btn type=“link” collapse=“a2”>See Answer</btn>

  (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) $(1,1)$
  <btn type=“link” collapse=“a3”>See Answer</btn>

  (a): $(0,0)$

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

• (a) $|z|$
• (b) $1 / z$
• (c) $-z$
• (d) $\bar{z}$
  <btn type=“link” collapse=“a4”>See Answer</btn>

  (d): $\bar{z}$

v. In complex plane imaginary part is drawn along

• (a) $x$-axis
• (b) $y$-axis
• (c) origin
• (d) $x y$-plane
  <btn type=“link” collapse=“a5”>See Answer</btn>

  (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) $\overline{z_{1}}=-\overline{z_{2}}$
  <btn type=“link” collapse=“a6”>See Answer</btn>

  (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
  <btn type=“link” collapse=“a7”>See Answer</btn>

  (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) $\left(\frac{3}{25}, \frac{-4}{25}\right)$
  <btn type=“link” collapse=“a8”>See Answer</btn>

  (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) $-10 i$
  <btn type=“link” collapse=“a9”>See Answer</btn>

  (b): $-10$

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

• (a) $1$
• (b) $2$
• (c) $3$
• (d) $4$
  <btn type=“link” collapse=“a10”>See Answer</btn>

  (b): $2$