SSC JE Electrical Engineering 2017 Set 3 Paper

Capacitor is open circuit for DC signal.
$\mathrm{f}0,{\mathit{X}}_{\mathit{C}}=\frac{1}{2\mathit{\pi }\mathrm{fc}}$
${\mathit{X}}_{\mathit{C}}=\mathit{\infty }$ , open circuit
At low frequency $3{\mathit{C}}_{\mathit{C}}$ is open circuited and effect the low frequency response of amplifier At high frequency, short circuit and work as high pass filter. At low frequency ${\mathit{C}}_{\mathit{E}}$ is open circuit then reduce gain and at high frequency, short circuited so no reduction in gain and work as high pass filter. So effect at low frequency as resonance.
In ${\mathit{R}}_{\mathit{C}}$ coupled common emitter amplifier coupling capacitance and by pass capacitance effect the low frequency response.