I have done a simple electronic circuit with a bridge rectifier diode and I have observed an issue when I display the output signal. The output signal on some harmonic doesn't reach the 0 point as shown in the capture screen of my oscilloscope. Can any one explain the root cause of this issue? I have used the DF08 bridge rectifier.
This is generally caused by capacitance in the load and/or measuring device, or stray capacitance somewhere in the circuit. A high resistance load may not be able to discharge this capacitance fast enough to drop the voltage to zero during the zero crossing period.
In your case the effect is only occurring on every second half-cycle. This indicates an imbalance in the rectifier circuit, and suggests stray capacitance between the generator and ground may be the culprit.
I simulated your circuit in LTspice, first with the generator fully isolated and then with 15nF between its local ground and circuit ground.
Without stray capacitance:-
With stray capacitance:-