Question

Match List-I has four graphs showing variation of opposition to flow of ac versus frequency with circuit characteristic in List-II.

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (IV), (B) - (III), (C) - (II), (D) - (I)

Answer 1

The Correct Option is D

The given problem is to match List-I, which contains graphs showing the variation of opposition to the flow of AC versus frequency, with the corresponding circuit characteristics in List-II. The correct matching option is (A) - (IV), (B) - (III), (C) - (II), (D) - (I). Let's analyze the characteristics to confirm this match. 

1. (A) - (IV): The graph for an inductor, where the impedance increases linearly with frequency, matches the characteristic in option (IV), which represents inductive behavior. In an RL circuit, the opposition or inductive reactance X_L is directly proportional to frequency f (X_L = 2πfL).
2. (B) - (III): The graph showing impedance decreasing with frequency represents a capacitor, which corresponds to option (III). In an RC circuit, the capacitive reactance X_C is inversely proportional to frequency f (X_C = 1/(2πfC)).
3. (C) - (II): The graph indicating constant opposition regardless of the frequency is characteristic of a resistor, matching option (II). The resistor’s opposition is constant and independent of frequency.
4. (D) - (I): The graph with peak impedance at resonance matches the behavior of an RLC circuit, corresponding to option (I). The impedance is minimum at resonance and maximum when deviating from the resonant frequency due to the LC components.

Answer 2

List I - Opposition to AC and Frequency Relationships

List II - AC Circuit Elements/Concepts

• (A) Constant opposition to AC regardless of frequency: (IV) Resistance
  • Resistance (R) remains constant in an AC circuit, irrespective of the frequency of the applied signal.
• (B) Opposition to AC increases linearly with frequency: (III) Inductive reactance
  • Inductive reactance (X_L) is directly proportional to frequency (f), as given by the formula X_L = 2πfL, where L is the inductance.
• (C) Opposition to AC decreases with increasing frequency: (II) Capacitive reactance
  • Capacitive reactance (X_C) is inversely proportional to frequency (f), as given by the formula X_C = 1/(2πfC), where C is the capacitance.
• (D) Opposition to AC is frequency dependent and combines resistance and reactance effects: (I) Impedance
  • Impedance (Z) is the total opposition to current flow in an AC circuit, which includes both resistance (R) and reactance (X_L and X_C). It is frequency-dependent.

Therefore, the correct matching is:

• A - IV
• B - III
• C - II
• D - I

You have provided a clear and concise explanation for each pairing.