220-1101 Mobile Devices Practice Question
A user reports that their Android smartphone is getting very hot while charging and the battery drains rapidly even when idle. The charger and cable are known to be functional. The technician opens the device and notices the battery is slightly bulging. Which of the following is the MOST likely cause of the symptoms?
⚠ Common exam trap
The trap here is that candidates may attribute overheating solely to the charging port or power management IC, overlooking the physical symptom of a bulging battery as the definitive indicator of a failed cell.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Defective battery
A bulging battery indicates internal chemical degradation, often due to lithium-ion cell failure from overcharging, age, or manufacturing defects. This swelling can cause internal short circuits, leading to excessive heat generation during charging and rapid self-discharge even when idle. Since the charger and cable are known functional, the battery itself is the most likely root cause.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Defective battery
Why this is correct
A swollen battery is definitive evidence of internal cell damage: lithium-ion cells generate gas when their electrolyte decomposes due to overcharging, internal short circuits, or manufacturing defects. This internal fault raises the cell's internal resistance, creating excess heat during charging and causing rapid self-discharge when idle. The safe, correct action is immediate battery replacement and proper disposal.
- ✗
Faulty charging port
Why it's wrong here
A worn or damaged charging port typically produces intermittent connection and localized resistance heating at the USB connector, not a hot, bulging battery. While a poor connection can make the charger work harder, it cannot generate the internal gas pressure that causes visible battery swelling. Since the symptom is the battery's physical deformation and rapid idle drain, the port is ruled out as the primary cause.
When this WOULD be correct
A user reports that their smartphone charges intermittently and only works when the cable is held at a certain angle. The charger and cable are known functional. In this scenario, a faulty charging port would be the most likely cause.
- ✗
Failed power management IC
Why it's wrong here
A failed power management IC can cause charging anomalies and heat due to improper voltage regulation, but it is a controller chip, not the sealed cell that physically swells. The visible bulging indicates the battery's own internal short circuit or electrolyte breakdown, which is a mechanical-chemical failure unrelated to the PMIC's logic. Thus, the PMIC could be a contributing factor in an overcharge scenario, but the primary failed part requiring replacement is the battery.
When this WOULD be correct
A user reports that their smartphone gets hot while charging and the battery drains quickly, but the battery appears normal and the charger/cable are functional. The technician finds no physical damage. In this case, a failed power management IC would be the most likely cause.
- ✗
Damaged screen
Why it's wrong here
A cracked or malfunctioning display is electrically isolated from the battery charging path, so it cannot make the battery overheat or deplete quickly by itself. The only scenario in which screen damage causes battery drain is a stuck-on backlight, but even that would not produce a swollen or hot battery during charging. The user's report points to the battery's chemical/electrical health, not the display assembly.
When this WOULD be correct
A user reports that their smartphone's display shows flickering, lines, or black spots after a drop. The device otherwise functions normally. In this scenario, a damaged screen is the most likely cause.
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.
✓Defective batteryCorrect answer▾
Why this is correct
A swollen battery is definitive evidence of internal cell damage: lithium-ion cells generate gas when their electrolyte decomposes due to overcharging, internal short circuits, or manufacturing defects. This internal fault raises the cell's internal resistance, creating excess heat during charging and causing rapid self-discharge when idle. The safe, correct action is immediate battery replacement and proper disposal.
✗Faulty charging portWrong answer — click to see why▾
Why this is wrong here
A bulging battery directly indicates a defective battery, not a faulty charging port. The charging port could cause charging issues but not battery swelling or rapid drain when idle.
★ When this WOULD be the correct answer
A user reports that their smartphone charges intermittently and only works when the cable is held at a certain angle. The charger and cable are known functional. In this scenario, a faulty charging port would be the most likely cause.
Why candidates choose this
Candidates may associate overheating while charging with charging port issues, overlooking the clear physical sign of a bulging battery which points to battery failure.
✗Failed power management ICWrong answer — click to see why▾
Why this is wrong here
A failed power management IC could cause overheating and battery drain, but the bulging battery is a physical indicator of a defective battery, not a failed IC. The symptoms are directly explained by the battery's internal failure.
★ When this WOULD be the correct answer
A user reports that their smartphone gets hot while charging and the battery drains quickly, but the battery appears normal and the charger/cable are functional. The technician finds no physical damage. In this case, a failed power management IC would be the most likely cause.
Why candidates choose this
Candidates may associate overheating and rapid battery drain with power management issues, overlooking the physical evidence of a bulging battery that directly points to a defective battery.
✗Damaged screenWrong answer — click to see why▾
Why this is wrong here
A damaged screen does not cause battery overheating, bulging, or rapid drain. Screen damage typically results in display issues like cracks, dead pixels, or touch unresponsiveness, not power-related symptoms.
★ When this WOULD be the correct answer
A user reports that their smartphone's display shows flickering, lines, or black spots after a drop. The device otherwise functions normally. In this scenario, a damaged screen is the most likely cause.
Why candidates choose this
Candidates may associate any physical damage with battery problems, or think that a damaged screen could short-circuit and cause heating, but screen damage does not directly affect battery behavior.
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?”
Go deeper
Related to this question
About these practice questions
This 220-1101 question is part of Courseiva's 896-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1101 exam.