In cabling terminology, what does the letter P denote?

• A. Phase
• B. Plenum
• C. Protected
• D. Power

Answer: (B)

The concept being tested is what the P label on cabling stands for in terms of installation environments. The P indicates Plenum, meaning the cable is plenum-rated for use in air-handling spaces such as above ceilings or in ventilation ducts. Plenum-rated cables have fire-retardant jackets and produce limited smoke and toxic fumes if they burn, which is required in areas where airflow can spread smoke quickly.

This is not about electrical phase or power characteristics, and it isn’t indicating protection or armor. Those terms describe other aspects of wiring but not the specific environmental rating that the P label conveys.