The line in the complex plane corresponding to zero real part i.e. R [Z] = 0 is called Imaginary Axis.
Imaginary Axis is the y-axis of a complex plane or Argand diagram.

From the above figure, the x-axis is known as the real axis whereas the y-axis is known as the imaginary axis.

A. Graph 2
B. Graph 3
C. Graph 1
D. None of the above
Correct Answer: B
Step 1: On a complex plane or Argand diagram, y-axis represents the imaginary axis.
Step 2: From the graphs given above, Graph 3 represents the point P on the imaginary axis as the point P in Graph 1 and 2 is on the real axis.
Step 3: Hence Graph 3 represents the point P on the imaginary axis.
Q1: Which of the following points lies on the imaginary axis?
Q2: If a complex number 'z' lies on the imaginary axis, what is its real part?
Q: What does the imaginary axis represent?
A: It represents all complex numbers with a real part of zero.
Q: How is the imaginary axis related to the complex plane?
A: It forms the vertical axis of the complex plane, with the real axis forming the horizontal axis.