,BASIC ARRHYTHMIA SENTARA TEST COMPLETE
2025/2026
300 Practice Questions with Correct Answers & Detailed
Rationales
GRADED A+ | 2026 Update | 100% Verified Solutions
SECTION 1: ECG BASICS & CARDIAC ANATOMY (Questions
1–30)
Question 1
What does the P wave represent on an ECG?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Answer: B. Atrial depolarization
Rationale: The P wave represents atrial depolarization (contraction). It reflects the
electrical impulse spreading through the atria from the SA node.
Question 2
What does the QRS complex represent?
A. Atrial depolarization
B. Ventricular repolarization
,C. Ventricular depolarization
D. Purkinje fiber repolarization
Answer: C. Ventricular depolarization
Rationale: The QRS complex represents ventricular depolarization (contraction). This is
the largest waveform on the ECG.
Question 3
What is the normal duration of the PR interval in an adult?
A. 0.04–0.08 seconds
B. 0.06–0.10 seconds
C. 0.12–0.20 seconds
D. 0.20–0.32 seconds
Answer: C. 0.12–0.20 seconds
Rationale: The normal PR interval length is 0.12–0.20 seconds.
Question 4
What is the normal duration of the QRS complex in an adult?
A. 0.04–0.08 seconds
B. 0.06–0.12 seconds
C. 0.12–0.20 seconds
D. 0.20–0.32 seconds
Answer: B. 0.06–0.12 seconds
Rationale: The normal QRS interval length is 0.06–0.12 seconds. In adults, the normal
duration of the QRS complex should be 0.11 seconds or less.
, Question 5
What is the normal duration of the QT interval?
A. 0.12–0.20 seconds
B. 0.20–0.32 seconds
C. 0.32–0.44 seconds
D. 0.44–0.56 seconds
Answer: C. 0.32–0.44 seconds
Rationale: The normal QT interval length is 0.32–0.44 seconds.
Question 6
What is the length of one small square on standard EKG paper?
A. 0.02 seconds
B. 0.04 seconds
C. 0.08 seconds
D. 0.20 seconds
Answer: B. 0.04 seconds
Rationale: Each small square on EKG paper represents 0.04 seconds.
Question 7
What is the length of one large square (5 small squares) on standard EKG paper?
A. 0.04 seconds
B. 0.08 seconds
C. 0.16 seconds
D. 0.20 seconds
Answer: D. 0.20 seconds
2025/2026
300 Practice Questions with Correct Answers & Detailed
Rationales
GRADED A+ | 2026 Update | 100% Verified Solutions
SECTION 1: ECG BASICS & CARDIAC ANATOMY (Questions
1–30)
Question 1
What does the P wave represent on an ECG?
A. Ventricular depolarization
B. Atrial depolarization
C. Ventricular repolarization
D. Atrial repolarization
Answer: B. Atrial depolarization
Rationale: The P wave represents atrial depolarization (contraction). It reflects the
electrical impulse spreading through the atria from the SA node.
Question 2
What does the QRS complex represent?
A. Atrial depolarization
B. Ventricular repolarization
,C. Ventricular depolarization
D. Purkinje fiber repolarization
Answer: C. Ventricular depolarization
Rationale: The QRS complex represents ventricular depolarization (contraction). This is
the largest waveform on the ECG.
Question 3
What is the normal duration of the PR interval in an adult?
A. 0.04–0.08 seconds
B. 0.06–0.10 seconds
C. 0.12–0.20 seconds
D. 0.20–0.32 seconds
Answer: C. 0.12–0.20 seconds
Rationale: The normal PR interval length is 0.12–0.20 seconds.
Question 4
What is the normal duration of the QRS complex in an adult?
A. 0.04–0.08 seconds
B. 0.06–0.12 seconds
C. 0.12–0.20 seconds
D. 0.20–0.32 seconds
Answer: B. 0.06–0.12 seconds
Rationale: The normal QRS interval length is 0.06–0.12 seconds. In adults, the normal
duration of the QRS complex should be 0.11 seconds or less.
, Question 5
What is the normal duration of the QT interval?
A. 0.12–0.20 seconds
B. 0.20–0.32 seconds
C. 0.32–0.44 seconds
D. 0.44–0.56 seconds
Answer: C. 0.32–0.44 seconds
Rationale: The normal QT interval length is 0.32–0.44 seconds.
Question 6
What is the length of one small square on standard EKG paper?
A. 0.02 seconds
B. 0.04 seconds
C. 0.08 seconds
D. 0.20 seconds
Answer: B. 0.04 seconds
Rationale: Each small square on EKG paper represents 0.04 seconds.
Question 7
What is the length of one large square (5 small squares) on standard EKG paper?
A. 0.04 seconds
B. 0.08 seconds
C. 0.16 seconds
D. 0.20 seconds
Answer: D. 0.20 seconds
