Final answer:
The proper tension of an A/C 'V' drive belt can be determined using a ruler.
Step-by-step explanation:
The proper tension of an A/C 'V' drive belt can be determined using a ruler. A ruler is a tool that is used to measure the length or size of an object. In this case, the ruler can be used to measure the tension of the belt by checking the distance between the two points where the belt is being adjusted.