220-1101 Mobile Devices Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  The laptop is in battery saving mode, limiting USB power output

  Why this is correct

  When a laptop runs on battery or with a power-saving plan enabled, its embedded USB host controller can intentionally reduce the current supplied to downstream ports to conserve energy. Many laptops drop output to a baseline 500 mA (USB 2.0) or even 100 mA in extreme cases, which is far below the 2 A+ required for modern fast charging. This is a deliberate power-management policy, not a hardware fault, so the same phone charges normally from a wall adapter or from the laptop when it is plugged in.

• ✗

  The smartphone's USB-C port is damaged

  Why it's wrong here

  A damaged USB-C port (bent pins, debris, or a cracked connector) would hinder physical contact and current path for any source, so the phone would also charge slowly or fail to charge from the wall adapter. Since the phone fast-charges normally with the same adapter and cable, the port's positive/negative pins and CC (configuration channel) line are functionally intact. The symptom is isolated to the laptop's USB output, which points upstream to the host's power provisioning, not the phone's receptacle.

  When this WOULD be correct

  If the user reported that the phone charges slowly with any source (including wall outlet) and the cable is known good, then a damaged USB-C port on the phone would be the likely cause.

• ✗

  The cable is not rated for Power Delivery

  Why it's wrong here

  The cable's Power Delivery rating is proven sufficient by the phone charging quickly when connected to the wall adapter with the same cable. USB power negotiation is source-dependent: a wall adapter offers high current over any properly wired cable that supports it, while a laptop in battery saving mode may refuse to negotiate high current regardless of cable capability. If the cable were deficient, it would choke fast charging from every source, so it cannot be the culprit here.

  When this WOULD be correct

  A user reports slow charging on both a laptop and a wall outlet with the same cable. The cable is old and not certified for Power Delivery. In that case, the cable's lack of PD support would be the cause.

• ✗

  The laptop's USB drivers are outdated

  Why it's wrong here

  Outdated or faulty USB drivers can cause enumeration problems, failed fast-charge negotiation, or the port defaulting to a basic USB device, but they do not physically limit the port's ability to output current. A driver issue would typically also produce errors (device not recognized, disconnects) rather than a slow-but-steady charge. The fact that charging is only slower—not absent—points to a power-management policy, not a communication stack problem.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 220-1101 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official 220-1101blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

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