PREP 2026 | VERIFIED PRACTICE
QUESTIONS, ANSWERS & DETAILED
RATIONALES | COMPLETE ECG/EKG STUDY
GUIDE FOR CERTIFICATION SUCCESS
• This EKG Technician Certification Exam Prep 2026 contains 200 verified practice
questions with detailed EXPERT RATIONALE designed to build your confidence and
reinforce core ECG/EKG concepts tested on certification exams.
• Study each question carefully, review the EXPERT RATIONALE even when you
answer correctly, and use this guide as your final checkpoint before sitting the
exam — covering rhythm interpretation, lead placement, cardiac anatomy,
arrhythmias, and clinical application.
QUESTION 1
Which wave on the ECG represents ventricular depolarization?
A) P wave
B) T wave
C) U wave
D) PR interval
E) QRS complex
Correct Answer: E) QRS complex
EXPERT RATIONALE: The QRS complex represents the electrical depolarization of
the ventricles, which triggers ventricular contraction. It follows the P wave (atrial
depolarization) and normally lasts 0.06–0.10 seconds.
QUESTION 2
What is the normal duration of the PR interval?
A) 0.04–0.06 seconds
,B) 0.06–0.10 seconds
C) 0.10–0.14 seconds
D) 0.12–0.20 seconds
E) 0.22–0.28 seconds
Correct Answer: D) 0.12–0.20 seconds
EXPERT RATIONALE: The PR interval reflects the time from atrial depolarization to
the beginning of ventricular depolarization, including the delay at the AV node.
Normal range is 0.12–0.20 seconds (3–5 small boxes on ECG paper).
QUESTION 3
Which lead is considered the best single lead for rhythm monitoring?
A) Lead I
B) Lead III
C) Lead II
D) aVR
E) V1
Correct Answer: C) Lead II
EXPERT RATIONALE: Lead II provides the clearest view of the P wave and QRS
complex, making it the most commonly used lead for continuous rhythm
monitoring. It runs parallel to the heart's electrical axis.
QUESTION 4
The T wave on an ECG represents:
A) Atrial depolarization
B) Ventricular depolarization
,C) Atrial repolarization
D) Ventricular repolarization
E) SA node firing
Correct Answer: D) Ventricular repolarization
EXPERT RATIONALE: The T wave represents the repolarization (recovery) of the
ventricles. It normally follows the QRS complex and is upright in most leads.
Inverted T waves may indicate ischemia or other cardiac pathology.
QUESTION 5
How many small squares equal one large square on standard ECG paper?
A) 2
B) 3
C) 4
E) 5
D) 10
Correct Answer: E) 5
EXPERT RATIONALE: Each large square on ECG paper contains 5 small squares.
Each small square represents 0.04 seconds horizontally and 0.1 mV vertically. Each
large square represents 0.20 seconds horizontally.
QUESTION 6
What is the standard paper speed for ECG recording?
A) 15 mm/sec
B) 20 mm/sec
C) 25 mm/sec
, D) 30 mm/sec
E) 50 mm/sec
Correct Answer: C) 25 mm/sec
EXPERT RATIONALE: The standard ECG paper speed is 25 mm per second. At this
speed, each small square equals 0.04 seconds and each large square equals 0.20
seconds horizontally.
QUESTION 7
A heart rate between 60–100 bpm is classified as:
A) Bradycardia
B) Tachycardia
C) Flutter
D) Normal sinus rhythm
E) Fibrillation
Correct Answer: D) Normal sinus rhythm
EXPERT RATIONALE: Normal sinus rhythm is defined by a rate of 60–100 bpm, a
regular rhythm, a P wave before every QRS, and a normal PR interval (0.12–0.20
seconds).
QUESTION 8
A heart rate below 60 bpm is called:
A) Tachycardia
B) Bradycardia
C) Asystole
D) Normal sinus rhythm