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.
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
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 $\left(\dfrac{1+i}{1-i}\right)^{n}=1$ then least positive value of $n$ is
(a) $1$
(b) $2$
(c) $3$
(d) $4$
See Answer(b): $2$