OSHA 10-Hour Construction Outreach (knowledge check)
Focus Four: Electrocution: practice questions
Our OSHA 10 Construction bank has 35 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
Under the 10-hour Construction Outreach program, what is the minimum class time for electrocution hazards?
- 30 minutes
- 1 hour and 30 minutes
- 10 minutes
- 4 hours
Show the answer
A. 30 minutes — Falls must get at least 1.5 hours; electrocution, struck-by and caught-in or between must each get at least 30 minutes, within 4 hours of Focus Four overall.
Question 2
What is the main purpose of lockout/tagout before working on electrical equipment?
- To make sure the equipment is de-energized and cannot be turned on while you work
- To label equipment with its purchase date and the name of the last person who serviced it
- To mark equipment that needs cleaning
- To keep tools from being stolen
Show the answer
A. To make sure the equipment is de-energized and cannot be turned on while you work — De-energizing, locking and tagging circuits prevents accidental re-energizing while workers are exposed.
Question 3
Who may work on energized electrical circuits?
- Any worker with an OSHA 10 card
- Qualified persons who are trained and protected for the work
- Apprentices working alone
- Any worker wearing rubber boots and leather gloves, as long as a coworker watches
Show the answer
B. Qualified persons who are trained and protected for the work — Only qualified persons may work on energized parts; others must keep clear of them.
Question 4
How much current can be enough to stop a heart (cause ventricular fibrillation)?
- A small fraction of an amp, such as 100 milliamps
- At least 50 amps
- Only more than 1,000 amps
- At least 15 amps, the rating of a standard household circuit breaker
Show the answer
A. A small fraction of an amp, such as 100 milliamps — OSHA training material notes that currents around 100 mA (0.1 amp) can cause ventricular fibrillation, far less than a 15-amp circuit breaker allows.
Question 5
A worker carrying a metal ladder near an overhead power line should:
- Raise the ladder upright to check whether it clears the line before carrying it past
- Use a metal ladder because it is stronger
- Touch the line briefly to test it
- Keep the ladder and themselves at a safe distance and carry it horizontally
Show the answer
D. Keep the ladder and themselves at a safe distance and carry it horizontally — Portable metal ladders must not be used near energized lines; keep conductive objects away from overhead lines.