CertHead

Hardware — A+ Core 1 practice questions

Domain 3 of the CompTIA A+ Core 1 (220-1101) exam. 225 questions on this domain in the full bank — here are four free samples with answers and explanations.

Question 1 · Difficulty 3/5

A building contractor is pulling new network cable through the air-handling space above a drop ceiling that serves as the HVAC return-air plenum. Which cable jacket rating is required by the NEC (National Electrical Code) in this location? (Select the best answer.)
  1. PVC (CMX)
  2. Riser (CMR)
  3. Plenum (CMP)
  4. Low-smoke zero-halogen (LSZH)
Show answer & explanation

Correct answer: C

Plenum (CMP)
NEC Article 800 requires CMP (Communications Plenum) rated cable in air-handling spaces because standard PVC jackets release toxic fumes when burned, which an HVAC system would circulate throughout the building. Riser (CMR) cable is rated for vertical runs between floors in non-plenum shafts and does not meet the stricter burn requirements of a plenum space. PVC/CMX is rated for outdoor or conduit use and is the most flammable of the jacket types. LSZH cable is common in Europe and data centers but is not itself the NEC classification used for U.S. plenum spaces; the required NEC designation is CMP.

Question 2 · Difficulty 3/5

A technician is reviewing the cable infrastructure of an older office building. The vertical cable runs travel through enclosed shafts between floors but do not pass through any air-handling spaces. Which cable jacket rating satisfies the NEC fire code for these vertical inter-floor runs while being less expensive than plenum-rated cable? (Select the best answer.)
  1. PVC (CMX)
  2. Plenum (CMP)
  3. Riser (CMR)
  4. Direct-burial (CMX/DB)
Show answer & explanation

Correct answer: C

Riser (CMR)
Riser (CMR) cable is specifically rated by NEC Article 800 for vertical runs in building shafts between floors where the cable is not in an air-handling space. CMR jackets resist flame spread vertically but do not meet the stricter CMP smoke and toxicity requirements. PVC/CMX is not rated for indoor vertical runs and would fail the NEC fire code in this application. Plenum (CMP) would also satisfy the fire code here because plenum cable can substitute for riser cable, but it costs significantly more and is not required when no air-handling space is involved. Direct-burial cable is designed for outdoor underground installation and is not an appropriate NEC rating for indoor vertical shafts.

Question 3 · Difficulty 3/5

A network technician is installing horizontal Ethernet runs in a standard office environment where the cable travels inside conduit within finished walls and does not pass through any air-handling or vertical floor-penetration pathways. Which cable jacket rating is acceptable and the most cost-effective choice for this installation? (Select the best answer.)
  1. CMP (plenum-rated)
  2. CMR (riser-rated)
  3. CM or CMG (general-purpose PVC)
  4. LSZH (low-smoke zero-halogen)
Show answer & explanation

Correct answer: C

CM or CMG (general-purpose PVC)
NEC Article 800 permits CM or CMG general-purpose PVC-jacketed cable for horizontal runs inside conduit in standard finished walls where neither plenum nor riser fire-spread requirements apply, making it the most cost-effective option. CMP (plenum) and CMR (riser) are required in air-handling spaces and vertical floor penetrations respectively; using them here is permissible but unnecessarily expensive. LSZH cable is a European standard required in confined spaces with poor ventilation and is not part of the NEC CMP/CMR/CM rating hierarchy, so selecting it does not satisfy a specific NEC code requirement in this context.

Question 4 · Difficulty 3/5

A network engineer is upgrading a wiring closet and discovers the existing horizontal cabling is Cat 5e. The engineer's manager asks whether the installed Cat 5e cabling can support Gigabit Ethernet (1000BASE-T) at the full 100-meter channel length. Which statement is accurate? (Select the best answer.)
  1. No, Cat 5e supports only 100 Mbps; 1 Gbps requires Cat 6 or higher.
  2. Yes, Cat 5e is rated for 1000BASE-T at up to 100 meters using all four wire pairs.
  3. Yes, but only if the run is under 55 meters; beyond that, Cat 6 is required.
  4. No, Cat 5e can carry 1 Gbps only when shielded (STP) cable is used.
Show answer & explanation

Correct answer: B

Yes, Cat 5e is rated for 1000BASE-T at up to 100 meters using all four wire pairs.
TIA-568-C.2 and IEEE 802.3ab (1000BASE-T) both specify Cat 5e as the minimum cable category for Gigabit Ethernet at the full 100-meter permanent-link channel length, utilizing all four wire pairs for simultaneous bidirectional signaling. The 55-meter limitation applies to Cat 6 when used for 10GBASE-T (10 Gbps), not to Cat 5e at 1 Gbps. Cat 5e does not require shielding for 1000BASE-T; the standard is defined for unshielded (UTP) cable. The claim that Cat 5e is limited to 100 Mbps confuses it with the older Cat 5 specification, which lacked the tighter crosstalk margins required for Gigabit.

More A+ Core 1 domains

Ready to test yourself for real?

The free quiz pulls live questions from the same banks — no account required.

Start the free quiz