CompTIA Updated 220-1101 Exam Questions and Answers by marlowe

The most likely reason that the technician is unable to select the channel with almost no RF pollution is that it is reserved for licensed band use. Some channels are reserved for specific purposes and require a license to use. These licensed bands are typically used for critical infrastructure, public safety, or military operations, and unlicensed devices are not allowed to use them. References: CompTIA A+ Certification Exam Objectives - 220-1001: 3.3 Compare and contrast common networking hardware devices.

Electromagnetic interference (EMI) is unwanted noise or interference in an electrical path or circuit caused by an outside source. Hence shielded Cat 6 is better

If a technician determines that the root cause of sporadic network connectivity issues is EMI, the most cost-effective cable medium that can be used without sacrificing system performance is shielded Cat 6 cable. Shielded cables protect against electromagnetic interference (EMI) and radio frequency interference (RFI). References: CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition by Mike Meyers (Page 548)

If users are experiencing decreased bandwidth and connectivity issues in a Wi-Fi mesh network, the technician should use a Wi-Fi analyzer to determine whether the channel in use is overcrowded and to identify which channel the mesh network should use for best performance. References: CompTIA A+ Certification Study Guide, Tenth Edition, pg. 308

Thin, vertical lines on every printed page are usually caused by a dirty drum or toner cartridge. Performing the drum-cleaning procedure will likely resolve the issue. References: CompTIA A+ Certification Exam Guide, Ninth Edition, Chapter 18