An AC voltage source of variable angular frequency $\omega$ and fixed amplitude $\mathrm{V}_{0}$ is

Question

An AC voltage source of variable angular frequency $\omega$ and fixed amplitude $\mathrm{V}_{0}$ is connected in series with a capacitance C and an electrical bulb of resistance R . (Inductance zero). When $\omega$ is decreased,\

Professor PC Thomas Classes · Answer

$\mathrm{P}=\mathrm{V}_{\mathrm{rms}} . \mathrm{I}_{\mathrm{rms}} \cos \phi$\ $=\frac{\mathrm{V}_{\mathrm{rms}}^{2} \mathrm{R}}{\mathrm{z}^{2}}$ where $\mathrm{z}=\sqrt{\mathrm{R}^{2}+\frac{1}{\omega \mathrm{c}}}$\ As $\omega$ decreases, Z increases, so P decreases\