Answer & Solution
Answer: Option C
Solution:
Let's understand this concept step by step.
A
parallel resonant circuit consists of a resistor (R), an inductor (L), and a capacitor (C) connected in parallel. It resonates at a particular frequency called the
resonant frequency.
The
bandwidth is the range of frequencies around the resonant frequency over which the circuit responds effectively. A
narrow bandwidth indicates high selectivity, while a
wide bandwidth indicates lower selectivity.
The selectivity of a parallel resonant circuit is measured by its
Quality Factor (Q-factor). For a parallel resonant circuit, the
Q-factor is directly proportional to the parallel resistance (R).
The relationship between bandwidth and Q-factor is:
Bandwidth = Resonant Frequency / Q-factor
This means that
bandwidth is inversely proportional to the Q-factor.
When the
parallel resistance is reduced, the
Q-factor decreases. As the Q-factor decreases, the
bandwidth increases, making the resonance curve broader and the circuit less selective.
Therefore,
reducing the resistance in parallel with a parallel resonant circuit increases its bandwidth.
Hence, the correct answer is
Option C: Increases.
