I observed the output signal of full-wave bridge rectifier sending sine wave and square wave for an experiment. In both of the output signals it is clear that each cycle shows one of the two different maximum voltage values and I have no idea why this happens. The bridge rectifier was built with 4 x 1N 4001 diodes which supposed to be identical and a 100 ohm resistor. The output signal across the resistor was observed. The schematic of the circuit is this.
The experiment was conducted in a freshman physics lab.