EGK REAL EXAM AND STUDY GUIDE TEST 150+ QUESTIONS
AND CORRECT ANSWERS WITH RATIONALES 2025-2026
LATEST//ALREADY GRADED A+
1. A medical assistant is preparing to perform a 12-lead EKG. Where should the V1
electrode be placed?
☑ A. 4th intercostal space at the right sternal border
☐ B. 5th intercostal space at the midclavicular line
☐ C. 2nd intercostal space at the left sternal border
☐ D. 6th intercostal space at the midaxillary line
Rationale: The V1 electrode is placed at the 4th intercostal space along the right sternal
border for accurate chest lead recordings.
2. Which EKG wave represents atrial depolarization?
☑ A. P wave
☐ B. QRS complex
☐ C. T wave
☐ D. U wave
Rationale: The P wave reflects the electrical activity of atrial depolarization before the
atria contract.
3. The QRS complex on an EKG represents which cardiac event?
☑ A. Ventricular depolarization
☐ B. Atrial depolarization
☐ C. Ventricular repolarization
☐ D. Atrial repolarization
Rationale: The QRS complex shows the electrical activation of the ventricles, initiating
ventricular contraction.
4. A patient’s EKG shows a PR interval longer than 0.20 seconds. What is the most
likely interpretation?
☑ A. First-degree AV block
☐ B. Ventricular tachycardia
☐ C. Atrial fibrillation
☐ D. Normal sinus rhythm
, Rationale: A prolonged PR interval indicates delayed conduction through the AV node,
characteristic of a first-degree AV block.
5. Which EKG wave represents ventricular repolarization?
☑ A. T wave
☐ B. P wave
☐ C. QRS complex
☐ D. PR segment
Rationale: The T wave corresponds to the ventricles returning to their resting electrical
state.
6. What is the normal heart rate range for an adult in sinus rhythm?
☑ A. 60–100 bpm
☐ B. 40–60 bpm
☐ C. 100–140 bpm
☐ D. 140–180 bpm
Rationale: A normal adult resting heart rate ranges from 60–100 beats per minute.
7. Which of the following can cause a wandering baseline on an EKG?
☑ A. Poor electrode contact or movement
☐ B. Ventricular fibrillation
☐ C. Sinus tachycardia
☐ D. Myocardial infarction
Rationale: Poor electrode attachment or patient movement can cause the EKG baseline to
shift.
8. The standard paper speed for a resting EKG is:
☑ A. 25 mm/sec
☐ B. 10 mm/sec
☐ C. 50 mm/sec
☐ D. 100 mm/sec
Rationale: EKGs are typically recorded at 25 mm/sec to standardize wave measurement.
, 9. A widened QRS complex (>0.12 sec) may indicate:
☑ A. Ventricular conduction delay or bundle branch block
☐ B. Normal sinus rhythm
☐ C. Atrial fibrillation
☐ D. Sinus bradycardia
Rationale: A widened QRS suggests slower ventricular depolarization, often due to a
bundle branch block or ventricular ectopic beats.
10. Which artifact is caused by electrical interference from nearby equipment?
☑ A. AC interference
☐ B. Wandering baseline
☐ C. Muscle tremor
☐ D. Motion artifact
Rationale: AC interference produces regular spikes on an EKG tracing due to nearby
electrical sources.
51. A patient’s EKG shows a rate of 110 bpm, regular rhythm, normal P waves, and
normal QRS complexes. What is the rhythm?
☑ A. Sinus tachycardia
☐ B. Sinus bradycardia
☐ C. Atrial fibrillation
☐ D. Ventricular tachycardia
Rationale: Sinus tachycardia is defined as a sinus rhythm with a rate over 100 bpm while
maintaining normal P waves and QRS complexes.
52. Which EKG lead monitors the right side of the heart?
☑ A. V1
☐ B. V5
☐ C. V6
☐ D. II
Rationale: Lead V1 is placed at the 4th intercostal space, right sternal border, and
monitors the right atrium and ventricle.
53. A patient’s EKG shows absent P waves, irregularly spaced QRS complexes, and an
irregular rhythm. What is the likely rhythm?
☑ A. Atrial fibrillation
AND CORRECT ANSWERS WITH RATIONALES 2025-2026
LATEST//ALREADY GRADED A+
1. A medical assistant is preparing to perform a 12-lead EKG. Where should the V1
electrode be placed?
☑ A. 4th intercostal space at the right sternal border
☐ B. 5th intercostal space at the midclavicular line
☐ C. 2nd intercostal space at the left sternal border
☐ D. 6th intercostal space at the midaxillary line
Rationale: The V1 electrode is placed at the 4th intercostal space along the right sternal
border for accurate chest lead recordings.
2. Which EKG wave represents atrial depolarization?
☑ A. P wave
☐ B. QRS complex
☐ C. T wave
☐ D. U wave
Rationale: The P wave reflects the electrical activity of atrial depolarization before the
atria contract.
3. The QRS complex on an EKG represents which cardiac event?
☑ A. Ventricular depolarization
☐ B. Atrial depolarization
☐ C. Ventricular repolarization
☐ D. Atrial repolarization
Rationale: The QRS complex shows the electrical activation of the ventricles, initiating
ventricular contraction.
4. A patient’s EKG shows a PR interval longer than 0.20 seconds. What is the most
likely interpretation?
☑ A. First-degree AV block
☐ B. Ventricular tachycardia
☐ C. Atrial fibrillation
☐ D. Normal sinus rhythm
, Rationale: A prolonged PR interval indicates delayed conduction through the AV node,
characteristic of a first-degree AV block.
5. Which EKG wave represents ventricular repolarization?
☑ A. T wave
☐ B. P wave
☐ C. QRS complex
☐ D. PR segment
Rationale: The T wave corresponds to the ventricles returning to their resting electrical
state.
6. What is the normal heart rate range for an adult in sinus rhythm?
☑ A. 60–100 bpm
☐ B. 40–60 bpm
☐ C. 100–140 bpm
☐ D. 140–180 bpm
Rationale: A normal adult resting heart rate ranges from 60–100 beats per minute.
7. Which of the following can cause a wandering baseline on an EKG?
☑ A. Poor electrode contact or movement
☐ B. Ventricular fibrillation
☐ C. Sinus tachycardia
☐ D. Myocardial infarction
Rationale: Poor electrode attachment or patient movement can cause the EKG baseline to
shift.
8. The standard paper speed for a resting EKG is:
☑ A. 25 mm/sec
☐ B. 10 mm/sec
☐ C. 50 mm/sec
☐ D. 100 mm/sec
Rationale: EKGs are typically recorded at 25 mm/sec to standardize wave measurement.
, 9. A widened QRS complex (>0.12 sec) may indicate:
☑ A. Ventricular conduction delay or bundle branch block
☐ B. Normal sinus rhythm
☐ C. Atrial fibrillation
☐ D. Sinus bradycardia
Rationale: A widened QRS suggests slower ventricular depolarization, often due to a
bundle branch block or ventricular ectopic beats.
10. Which artifact is caused by electrical interference from nearby equipment?
☑ A. AC interference
☐ B. Wandering baseline
☐ C. Muscle tremor
☐ D. Motion artifact
Rationale: AC interference produces regular spikes on an EKG tracing due to nearby
electrical sources.
51. A patient’s EKG shows a rate of 110 bpm, regular rhythm, normal P waves, and
normal QRS complexes. What is the rhythm?
☑ A. Sinus tachycardia
☐ B. Sinus bradycardia
☐ C. Atrial fibrillation
☐ D. Ventricular tachycardia
Rationale: Sinus tachycardia is defined as a sinus rhythm with a rate over 100 bpm while
maintaining normal P waves and QRS complexes.
52. Which EKG lead monitors the right side of the heart?
☑ A. V1
☐ B. V5
☐ C. V6
☐ D. II
Rationale: Lead V1 is placed at the 4th intercostal space, right sternal border, and
monitors the right atrium and ventricle.
53. A patient’s EKG shows absent P waves, irregularly spaced QRS complexes, and an
irregular rhythm. What is the likely rhythm?
☑ A. Atrial fibrillation
