Question

A full wave rectifier uses two diode, the internal resistance if each diode is `20Omega`. The transformer rms seconary voltage from centre tap tp each end of secondary is 50 V and load resistance is `980Omega`. Find (i) the mean load current (ii) the rms value of load current.

Answer 1

Here, `R_(i)=20Omega, R_(L)=980Omega, V_(rms)=50V`
Max. a.c. voltage, `V_(0)=50sqrt(2)=70.7V`
Max. load current, `I_(0)=V_(0)/(R_(i)+R_(L))=70.7/(20+980)=70.7xx10^(-3)A`
(i) Mean load current,
`I_(dc)=(2I_(0))/pi=(2xx(70.7xx10^(-3)))/3.14`
`=45xx10^(-3)=45mA`
(ii)rms value of load current
`I_(rms)=I_(0)/sqrt(2)=(70.7xx10^(-3))/1.414=50mA`