Concept:For a shunt capacitor filter, ripple is proportional to load current (\( r \propto I_{\text{dc}} \propto 1/R_L \)). For a series inductor filter, ripple is inversely proportional to load current (\( r \propto R_L \propto 1/I_{\text{dc}} \)).
Formula:$$r_{\text{capacitor}} = \frac{1}{2\sqrt{3} f C R_L} \propto \frac{I_{\text{dc}}}{C} \quad \text{vs} \quad r_{\text{inductor}} = \frac{R_L}{3\sqrt{2} \omega L} \propto \frac{1}{I_{\text{dc}} L}$$
Solution:- Capacitor filter: Higher load current discharges the capacitor faster between peaks, increasing ripple.
- Inductor filter: Higher current increases magnetic energy storage (\( \frac{1}{2} L I^2 \)), improving choke action and reducing ripple.
- Therefore, inductor filters are better suited for heavy loads (high current), while capacitor filters are better suited for light loads (low current).
Why other options are incorrect:- Option A: Inductor filters perform better at high load currents.
- Option B: This reverses the actual load dependencies of the two filters.
- Option C: Ripple factor in both filters depends strongly on load current.
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