Question

on circuits above ___, all exposed metal parts of portable control devices should be grounded by a grounding conductor in the control cable. 50 amps 50 volts 50 ohms 50 cal/cm2

Explanation:

Electrical safety standards state that on circuits above 50 volts, all exposed metal parts of portable control devices should be grounded to prevent electrical - shock hazards. Volts measure electric potential difference relevant to electrical safety in this context, while amps measure current, ohms measure resistance, and cal/cm² is a unit of energy density and not relevant here.

Answer:

50 volts