Question

In an impedance Smith chart, a clockwise movement along a constant resistance circle gives rise to

• A. a decrease in the value of reactance
• B. an increase in the value of reactance
• C. no change in the reactance value
• D. no change in the impedance value

Hint:

On a Smith Chart: - Clockwise: Towards Generator \(\implies\) Inductive \(\implies\) Reactance Increases. - Counter-Clockwise: Towards Load \(\implies\) Capacitive \(\implies\) Reactance Decreases.

Answer 1

The Correct Option is B

Step 1: Understand the Smith Chart axes. The Smith Chart plots the complex reflection coefficient. It has overlays of constant resistance circles and constant reactance arcs. The upper half of the chart represents positive (inductive) reactance, and the lower half represents negative (capacitive) reactance.
Step 2: Understand movement on the chart. Moving along a constant resistance circle means the real part of the impedance is fixed, while the imaginary part (reactance) changes. A clockwise movement on the Smith Chart corresponds to moving "towards the generator" or adding a length of transmission line.
Step 3: Relate clockwise movement to reactance. When moving clockwise along a constant resistance circle, one moves from the capacitive (lower) half, through the real axis (zero reactance), and into the inductive (upper) half. This represents a continuous increase in the value of reactance (from negative, through zero, to positive). Therefore, a clockwise movement corresponds to an increase in reactance.