Output Capacitor Ripple

Correct Answer

A — 48 μF

Concept and Reasoning

For an ideal boost converter, D=1−Vin/Vo=1−12/30=0.6. During the switch ON interval the capacitor supplies the load, so approximately ΔVo/Vo=D/(R C fs). Imposing a peak-to-peak ripple below 1% gives the minimum capacitance corresponding to option A.

Calculation / Key Relation

D=1−Vin/Vo

ΔVo/Vo≈D/(RCfs)

Exam Takeaway

Boost ripple sizing: capacitor supports the load during switch ON time.

Common Mistake

Use the stated peak-to-peak ripple limit consistently; do not treat it as peak ripple.