Concept:Full-wave rectifiers are used in DC power supplies because they provide higher efficiency (\( 81.2\% \) vs \( 40.6\% \)) and a higher ripple frequency, which simplifies smoothing.
Formula:$$\gamma = \frac{V_{\text{ac, rms}}}{V_{\text{dc}}} \implies \gamma_{\text{FW}} = 0.482 \quad \text{vs} \quad \gamma_{\text{HW}} = 1.21$$
Solution:- Sensitive electronics like smartphones and laptops require smooth DC voltage with minimal ripple.
- Full-wave rectifiers supply current during both input half-cycles and operate at twice the ripple frequency, making filtering with compact capacitors more effective.
Why other options are incorrect:- Options A, C, & D: Simple continuity testers, buzzers, and soldering iron heating circuits have low sensitivity to DC ripple and often use basic half-wave rectifiers.
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