Final answer:
Alternator ripple refers to fluctuations in the DC output of an alternator due to the incomplete conversion of AC to DC, and testing for alternator ripple is indeed used to assess the condition of the diode rectifier bridge within the alternator.
Step-by-step explanation:
The statement that 'alternator ripple is a test of the diode tree / rectifier bridge inside of the alternator' is true. The alternator ripple refers to the small fluctuations or 'ripples' in the DC output of an alternator, which occur due to the incomplete conversion of AC to DC by the diode rectifier bridge. When an alternator is functioning properly, the ripple should be minimal. However, if there are defects in the diode tree, the ripple will increase, indicating a problem. This test is important because excessive ripple can cause damage to the vehicle's electrical systems and affect the performance and longevity of the battery.