Question

The figure below shows a circuit for charging a 12-V battery. If Vs is a sinusoid with 24-V peak amplitude, the fraction of each cycle during which the diode conducts is

(a) One quarter of a cycle

(b) One-third of a cycle

(c) One half of the cycle

(d) Three quarters of a cycle

I had been asked this question by my college director while I was bunking the class.

My question is taken from The Ideal Diode in chapter Diodes of Electronic Devices & Circuits

Answer 1

Right option is (b) One-third of a cycle

For explanation I would say: For one half of the cycle the diode conducts when 24 cos(Θ) = 12 or Θ is 600. Hence for a complete cycle the diode does not conducts for 2Θ or 1200. Hence the diode does not conducts for a third of a cycle.