MCQ Test Page

  1. If $*$ is a binary operation in a set $A$, then for all $a, b \in A$
    1. $a+b \in A$
    2. $a-b \in A$
    3. $a \times b \in A$
    4. $a * b \in A$
  2. If $z=(1,3)$ then $z^{-1}= $
    1. $(\displaystyle{\frac{1}{10}},\displaystyle{\frac{3}{10}})$
    2. $(-\displaystyle{\frac{1}{10}},\displaystyle{\frac{3}{10}})$
    3. $(\displaystyle{\frac{1}{10}},-\displaystyle{\frac{3}{10}})$
    4. $(-\displaystyle{\frac{1}{10}},-\displaystyle{\frac{3}{10}})$
  3. $\displaystyle{\frac{3}{2+2i}}=$
    1. $1-i$
    2. $1+i$
    3. $-2i$
    4. $\displaystyle{\frac{3-3i}{4}}$
  4. $\overline{z_1+z_2}=$
    1. $\overline{z_1}+\overline{z_2}$
    2. $\overline{z_1}-\overline{z_2}$
    3. $\overline{z_1}+z_2$
    4. $z_1+\overline{z_2}$
  5. $|z_1+z_2|$
    1. $>|z_1|+|z_2|$
    2. $\leq|z_1|+|z_2|$
    3. $\leq z_1+z_2$
    4. $>z_1+z_2$
  6. If $z_1=2+i$, $z_2=1+3i$, then $z_1-z_2=$
    1. $1-7i$
    2. $-1+7i$
    3. $1-2i$
    4. $3+4i$
  7. If $z_1=2+i$, $z_2=1+3i$, then $-i lm (z_1-z_2)=$
    1. $2i$
    2. $-2i$
    3. $2$
    4. $3$
  8. Which of the following sets has closure property with respect to multiplication?
    1. $\{-1,1\}$
    2. $\{-1\}$
    3. $\{-1,0\}$
    4. $\{0,2\}$
  9. The multiplicative inverse of $2$ is
    1. $0$
    2. $1$
    3. $-2$
    4. $\displaystyle{\frac{1}{2}}$