Complex Numbers · NDA previous year questions

2026 3 questions

1. Q202026 · 12 Apr 2026

   Let $Z_1$ and $Z_2$ be complex numbers such that $\frac{3Z_1}{4Z_2}$ is purely imaginary. What is $\left|\frac{Z_1+Z_2}{Z_1-Z_2}\right|$ equal to ?

   1. A.2
   2. B.$\frac{3}{2}$
   3. C.$\frac{5}{4}$
   4. D.1
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   Answer: D

2. Q212026 · 12 Apr 2026

   Consider the following inequalities : I. $1+4i>3+2i$ II. $2+3i<3+4i$ III. $4+3i>3+4i$ where $i=\sqrt{-1}$ How many of the above are valid ?

   1. A.None
   2. B.One
   3. C.Two
   4. D.All the three
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   Answer: A

3. Q222026 · 12 Apr 2026

   Consider the following statements : I. $\sqrt{x}+x+1=0$ has two irrational roots. II. $5\sqrt{x}-x-4=0$ has two rational roots. Which of the statements given above is/are correct ?

   1. A.I only
   2. B.II only
   3. C.Both I and II
   4. D.Neither I nor II
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   Answer: B