Free CPE Practice Questions

Question 1

At a packing station, a worker lifts stable 15 kg cartons with both hands. The task is within the Revised NIOSH Lifting Equation's scope. The recommended weight limit is 18 kg at the origin and 10 kg at the destination, where each carton must be held while precisely positioned. Which finding should drive the redesign priority?

Accepted Answer

A lifting index of 1.50; controlled placement makes the destination's lower recommended weight limit govern this task.

Answer

A lifting index of 0.83; the origin determines whether the carton can be lifted acceptably.

Answer

A lifting index of 1.07; the two recommended weight limits should be averaged before evaluation.

Answer

A lifting index of 0.67; dividing the destination limit by the load indicates acceptable demand.

Question 2

A seated console will be sized using 5th-to-95th-percentile accommodation targets for each relevant body dimension. Task-specific data show functional forward reach of 540 mm at the 5th percentile and 700 mm at the 95th; seat-to-top-of-thigh height is 120 mm and 180 mm, respectively. Measurements include work clothing. Control distances use the same seat reference as the reach measurements. Which preliminary specification applies the reach and clearance data in the correct directions?

Accepted Answer

Place the control 500 mm from the reference; provide 200 mm of clearance above the seat.

Answer

Place the control 680 mm from the reference; provide 200 mm of clearance above the seat.

Answer

Place the control 500 mm from the reference; provide 140 mm of clearance above the seat.

Answer

Place the control 680 mm from the reference; provide 140 mm of clearance above the seat.

Question 3

In two laboratory sessions, inspectors classify matched sets of defective and acceptable parts. Lighting, defect prevalence, viewing time, and task difficulty are held constant. The hit rate rises from 70% to 90%, while the false-alarm rate rises from 10% to 30%. What change in the decision process is most consistent with both movements?

Accepted Answer

A more liberal criterion for calling a part defective.

Answer

A more conservative threshold for classifying defects.

Answer

Better perceptual discrimination of defective from acceptable parts.

Answer

Poorer discrimination between the sensory evidence for defective and acceptable parts.

Question 4

An industrial dosing interface uses one numeric field for either total volume in mL or flow rate in mL/h. The active mode is shown only when the screen opens. After moving between screens, experienced operators sometimes submit correctly typed numbers with the wrong meaning. Both modes must remain available, and these numbers are valid in either mode. Which redesign addresses the failure at its source?

Accepted Answer

Keep the active mode and its units visible beside the entry field.

Answer

Require a generic confirmation before transmitting each numeric entry.

Answer

Reject numbers outside the allowable range for the currently selected mode before accepting an entry.

Answer

Provide additional practice switching modes and interpreting values before permitting independent equipment use.

Question 5

To compare two handheld scanners, a team recruits the same 24 warehouse workers to use both devices on equivalent picking tasks. Completion time is the main outcome, and errors are recorded separately. The draft protocol gives every worker scanner A first. How should the comparison be strengthened before testing?

Accepted Answer

Assign 12 workers to each device order, with equal practice and matched picking tasks for both scanners.

Answer

Give everyone identical training, then retain the A-first sequence to keep the procedure uniform.

Answer

Retain the A-first sequence and double the participant count to reduce the effect of order.

Answer

Have everyone repeat A until their times stabilize, then record a single measured trial with B.

Question 6

An ergonomist models a worker holding an instrument with the forearm horizontal. The forearm and hand weigh 20 N and act 0.15 m from the elbow; the instrument weighs 40 N and acts 0.30 m from the elbow. A single elbow flexor has a perpendicular moment arm of 0.03 m. Assume static equilibrium and ignore antagonist activity. What flexor force does this model predict, and what happens if the instrument is brought closer without changing the other geometry?

Accepted Answer

500 N; bringing the instrument closer reduces the required flexor force.

Answer

400 N; bringing the instrument closer reduces the required flexor force.

Answer

60 N; bringing the instrument closer leaves the required flexor force unchanged.

Answer

600 N; bringing the instrument closer reduces the required flexor force.

Question 7

A packaging line rotates employees every 30 minutes among labeling, trimming, and connector assembly. The task names differ, but observations show forceful pinch grips and sustained wrist deviation at all three stations. Which revision would make rotation more likely to reduce cumulative hand-wrist exposure?

Accepted Answer

Include tasks with substantially lower grip demands and different movement patterns.

Answer

Shorten the rotation intervals while retaining the same three-task sequence throughout each shift.

Answer

Reverse the station sequence on alternate days so employees encounter the tasks in different orders.

Answer

Let employees choose the order of the existing stations.

Question 8

Following a control-room redesign, the mean Raw NASA-TLX score remains 44 out of 100. Mental-demand ratings fall, while temporal-demand ratings rise; the remaining four dimensions change little. The project lead concludes that nothing about workload changed. How should the ergonomist interpret these results?

Accepted Answer

The total masks a shift between types of perceived demand.

Answer

The stable total establishes equivalent workload.

Answer

The mental-demand decrease demonstrates an overall workload improvement despite the unchanged total score.

Answer

The temporal-demand increase demonstrates worse task accuracy even without observations of actual performance.

Question 9

While observing outdoor paving during a heatwave, an ergonomist sees a worker become confused and stagger. The worker is sweating heavily and cannot reliably answer questions. Emergency communication and cooling supplies are immediately available. What takes priority?

Accepted Answer

Activate emergency medical care and begin rapid cooling immediately.

Answer

Provide shade and drinking water, then reassess.

Answer

Stop the worker's exertion and obtain a core temperature before activating emergency medical help.

Answer

Arrange a supervised ride to the occupational clinic after changing out of hot work clothing.

Question 10

An interface evaluation estimates that a redesign saves 0.6 seconds per transaction, with a 95% confidence interval of 0.2 to 1.0 seconds for the mean saving. Before testing, the team defined a 3-second reduction as the minimum worthwhile improvement. Accuracy is unchanged. Which statement belongs in the decision memo?

Accepted Answer

An improvement is supported, but its size falls short of the stated practical target.

Answer

Statistical uncertainty prevents a conclusion about the direction of change.

Answer

The result meets the practical target because the entire confidence interval favors the redesign.

Answer

The interval means 95% of individual users save between 0.2 and 1.0 seconds per transaction.

Free CPE Practice Questions

Domain 1: Analyze 38% of exam

Question 1

Question 2

Question 3

Question 4

Domain 2: Design 40% of exam

Question 5

Question 6

Question 7

Question 8

Domain 3: Integrate (Implement-Validate) 22% of exam

Question 9

Question 10

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