OSHA 10-Hour General Industry Outreach (knowledge check)
Electrical: practice questions
Our OSHA 10 General Industry bank has 31 questions on this topic. Here are 4 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
After a circuit breaker trips, what must happen before the circuit is turned back on?
- Reset it immediately to keep work going
- Reset it repeatedly until it stays on, since breakers sometimes trip for no reason
- Replace it with a larger breaker so it does not trip again
- Someone must determine that the equipment and circuit can be safely energized
Show the answer
D. Someone must determine that the equipment and circuit can be safely energized — After a protective device opens a circuit, it may not be manually reenergized until it is determined the equipment and circuit can be safely energized; repeated manual reclosing is prohibited.
Question 2
May employees plug or unplug energized equipment with wet hands?
- No
- Yes, if the cord is new
- Yes, if they wear a hard hat
- Yes, if the plug is the grounding type with three prongs
Show the answer
A. No — Employees' hands may not be wet when plugging and unplugging flexible cords and cord- and plug-connected equipment, if energized equipment is involved.
Question 3
What must protect the connections of flexible cords to devices and fittings?
- Strain relief, so pull is not transmitted to joints or terminal screws
- Electrical tape wrapped around the plug
- A knot tied in the cord near the plug
- A heavier fuse that will not blow when the cord is pulled hard
Show the answer
A. Strain relief, so pull is not transmitted to joints or terminal screws — Flexible cords must be connected to devices and fittings so that strain relief prevents pull from being transmitted directly to joints or terminal screws.
Question 4
What is the minimum depth of clear working space in front of equipment of 0–150 volts to ground (Table S-1)?
- 3 feet
- 1 foot
- 6 feet, measured from the wall behind the equipment
- 10 feet
Show the answer
A. 3 feet — Table S-1 sets a minimum clear distance of 3 feet for 0–150 volts to ground in all three conditions; deeper space is needed at 151–600 volts in some conditions.