Chapter 2: Complex Numbers - Online Test
Q1. If | z1 |
= 1, | z2 | = 2, | z3 | = 3 and | 9z1 z2
+ 4z1 z3 + z2 z3 | = 12 , then the value of | z1 + z2 + z3 | is
Answer : Option B
Explaination / Solution:
Q2. If z is a complex
number such that z ∈ C \R and z + 1/z ∈ R , then | z | is
Answer : Option B
Explaination / Solution:
Q3. z1 , z3 , and z3 are complex numbers
such that z1 + z2 + z3 = 0 and | z1 | =| z2 | =| z3 | = 1 then z 2 + z 2 + z 2 is
Answer : Option D
Explaination / Solution:
Q4. If (z-1) / (z+1), is purely
imaginary, then | z | is
Answer : Option B
Explaination / Solution:
Q5. If z = x + iy is a complex number such that | z + 2 | = | z − 2 | , then the locus of z
is
Answer : Option B
Explaination / Solution:
Q6. The principal argument of
3/(-1+i ) is
Answer : Option C
Explaination / Solution:
Q7. The principal argument of
(sin 40°+ i cos 40°)5 is
Answer : Option A
Explaination / Solution:
Q8. If (1+ i) (1+ 2i) (1+ 3i)L(1+ ni) = x + iy , then 2 ⋅ 5 ⋅10L(1+ n2 ) is
Answer : Option C
Explaination / Solution:
Q9. If ω ≠ 1 is a cubic root of unity and (1+ ω)7 = A + Bω , then ( A, B) equals
Answer : Option D
Explaination / Solution:
Q10. The principal argument of
the complex number 
is
is
Answer : Option D
Explaination / Solution:
