If $z$ is a complex number, then $z.\,\overline z = 0$ if and only if

  • A

    $z = 0$

  • B

    ${\mathop{\rm Re}\nolimits} (z) = 0$

  • C

    ${\mathop{\rm Im}\nolimits} \,(z) = 0$

  • D

    None of these

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If $z_1, z_2, z_3$ $\in$  $C$ such that $|z_1| = |z_2| = |z_3| = 2$, then greatest value of expression $|z_1 - z_2|.|z_2 - z_3| + |z_3 - z_1|.|z_1 - z_2| + |z_2 - z_3||z_3 - z_1|$ is

Let $\bar{z}$ denote the complex conjugate of a complex number $z$. If $z$ is a non-zero complex number for which both real and imaginary parts of

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The correct option is:

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