If the resistance in parallel with a parallel resonant circuit is reduced, the bandwidth

Answer: Option C

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.