Question

A half wave rectifier, operated from a 50Hz supply uses a 1000µF capacitance connected in parallel to the load of rectifier. What will be the minimum value of load resistance that can be   connected across the capacitor if the ripple% not exceeds 5?

(a) 114.87Ω

(b) 167.98Ω

(c) 115.47Ω

(d) 451.35Ω

I had been asked this question in an interview for internship.

This interesting question is from Capacitor Filters in portion Application of Diodes of Electronic Devices & Circuits

Answer 1

Correct option is (c) 115.47Ω

Easy explanation: For a half wave filter,

ϒ=1/2√3 fCRL=1/2√3*50*10^-3*RL

RL=10^3/5√3=115.47Ω.