4.72 a full-wave bridge-rectifier circuit with a 1-k load operates from a 120-v (rms) 60-hz household supply through a 12-to-1 step-down transformer having a single secondary winding. it uses four diodes, each of which can be modeled to have a 0.7-v drop for any current. what is the peak value of the rectified voltage across the load? for what fraction of a cycle does each diode conduct? what is the average voltage across the load? what is the average current through the load? d 4.73 i

a) 12.74 V

b) Two pairs of diode will work only half of the cycle

c) 8.11 V

d) 8.11 mA

Explanation:

The voltage after the transformer is relationated with the transformer relationshinp:

the peak voltage before the bridge rectifier is given by:

The diodes drop 0.7v, when we use a bridge rectifier only two diodes are working when the signal is positive and the other two when it's negative, so the peak voltage of the load is:

As we said before only two diodes will work at a time, because the signal is half positive and half negative,so two of them will work only half of the cycle.

The averague voltage on a full wave rectifier is given by:

Using Ohm's law: