1
TS EAMCET 2020 (Online) 10th September Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $z_1=x_1+i y_1, z_2=x_2+i y_2, z_3=x_1+\frac{i x_2}{2}, z_4=2 y_1+i y_2$ are complex numbers such that $\left|z_1\right|=1,\left|z_2\right|=2$ and $\operatorname{Re} \left(\begin{array}{ll}z_1 & z_2\end{array}\right)=0$, then

A

$\left|z_3\right|=1,\left|z_4\right|=2, \operatorname{Im}\left(z_3 z_4\right)=0$

B

$\left|z_3\right|=2,\left|z_4\right|=1, \operatorname{Re}\left(z_3 z_4\right)=0$

C

$\left|z_3\right|=1,\left|z_4\right|=2, \operatorname{Re}\left(z_3 z_4\right)=0$

D

$\left|z_3\right|=2,\left|z_4\right|=1, \operatorname{Re}\left(z_1 z_3\right)=\operatorname{Im}\left(z_2 z_4\right)=0$

2
TS EAMCET 2020 (Online) 10th September Evening Shift
MCQ (Single Correct Answer)
+1
-0

Assertion (A) If $z$ is a complex number such that $|z| \geq 3$, then the least value of $\left|z+\frac{3}{z}\right|$ is 1 .

Reason (R) $\left|z_1-z_2\right| \leq\left|z_1\right|+\left|z_2\right|$, for any two complex numbers $z_1, z_2$

The correct option among the following is

A

(A) is true, (R) is true and (R) is the correct explanation for (A).

B

(A) is true, (R) is true but (R) is not the correct explanation for (A).

C

(A) is true but (R) is false.

D

(A) is false but (R) is true.

3
TS EAMCET 2020 (Online) 10th September Evening Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { If }\left(\frac{\cos \theta+i \sin \theta}{\sin \theta+i \cos \theta}\right)^{2020}+\left(\frac{1+\cos \theta+i \sin \theta}{1-\cos \theta+i \sin \theta}\right)^{2021}=x+i y, $$

then the value of $x+y$ at $\theta=\frac{\pi}{2}$ is

A

2

B

1

C

-1

D

2020

4
TS EAMCET 2020 (Online) 10th September Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $\omega$ is a complex cube root of unity, then $\sum_{x=1}^{10}\left((\omega x+2)\left(\omega^2 x+2\right)-3\right)$

A

285

B

945

C

1025

D

705

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