Final answer:
The minimum load used when calculating branch circuit requirements for a dryer is determined by the power rating specified by the manufacturer of the appliance.
Step-by-step explanation:
When calculating branch circuit requirements for a dryer, the minimum load used is typically determined by the manufacturer's specifications. The electrical appliance, in this case, the dryer, is labeled with its power rating in watts or amperes. This rating indicates the amount of power it requires to operate properly. To determine the minimum load, you would use the power rating of the dryer, which is often mentioned on the appliance or in the accompanying documentation.