In a series $$LCR$$ resonance circuit, if we change the resistance only, from a lower to higher value:

In a series $$LCR$$ circuit, the resonance frequency is $$\omega_0 = \frac{1}{\sqrt{LC}}$$, which is independent of resistance $$R$$. So changing $$R$$ does not affect the resonance frequency.

The quality factor is $$Q = \frac{\omega_0 L}{R} = \frac{1}{R}\sqrt{\frac{L}{C}}$$. Increasing $$R$$ decreases the quality factor.

The bandwidth of the resonance circuit is defined as $$\Delta\omega = \frac{R}{L}$$. When $$R$$ increases from a lower to a higher value, the bandwidth $$\Delta\omega$$ increases, meaning the resonance peak becomes broader and less sharp.

Therefore, increasing resistance increases the bandwidth of the resonance circuit.