Question

when using a dmm to check for surface discharge across the top of a battery anything above volts indicates the battery needs to be cleaned. 0.2 0.5 1.0 none - a battery cannot discharge due to a dirty surface

Explanation:

When using a Digital Multimeter (DMM) to check for surface discharge across the top of a battery, if the reading is above 0.5 volts, it indicates that the battery needs to be cleaned. This is because dirt and debris on the battery surface can cause a small electrical path, leading to a measurable voltage drop which is an indication of surface discharge.

Answer:

0.5