NCCT Electrocardiograph Technician
Certification Exam (NCET) Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following best describes the function of an
electrocardiograph?
A. Measures blood pressure
B. Records the electrical activity of the heart
C. Measures oxygen saturation
D. Monitors brain waves
Rationale: The electrocardiograph (ECG) records the heart's electrical
impulses to detect arrhythmias, myocardial infarctions, and other
cardiac conditions.
,2. What is the standard speed at which ECG paper moves during a
recording?
A. 10 mm/sec
B. 20 mm/sec
C. 25 mm/sec
D. 50 mm/sec
Rationale: Standard ECG paper speed is 25 mm/sec, which allows
accurate interpretation of heart rate and waveform intervals.
3. Which lead is considered the "ground" lead in a standard 12-lead ECG?
A. RA (Right Arm)
B. LA (Left Arm)
C. LL (Left Leg)
D. RL (Right Leg)
Rationale: The right leg (RL) electrode serves as a ground to reduce
electrical interference in the ECG recording.
4. Which wave on an ECG represents atrial depolarization?
A. QRS complex
B. ST segment
C. P wave
D. T wave
, Rationale: The P wave corresponds to atrial depolarization, which
triggers atrial contraction.
5. Which interval represents the time between atrial and ventricular
depolarization?
A. PR interval
B. QT interval
C. PR segment
D. ST segment
Rationale: The PR segment is the flat line between the end of the P
wave and the start of the QRS complex, representing the conduction
delay through the AV node.
6. How many electrodes are used in a standard 12-lead ECG?
A. 6
B. 8
C. 10
D. 12
Rationale: A 12-lead ECG uses 10 electrodes: 4 limb electrodes and 6
chest electrodes to generate 12 views of the heart.
, 7. Which ECG change is commonly seen in hyperkalemia?
A. ST depression
B. Peaked T waves
C. Inverted P waves
D. Wide QRS with short PR
Rationale: Hyperkalemia can cause tall, peaked T waves due to
altered repolarization.
8. What is the normal duration of the QRS complex?
A. 0.04–0.06 sec
B. 0.06–0.10 sec
C. 0.10–0.14 sec
D. 0.14–0.20 sec
Rationale: A normal QRS duration ranges from 0.06 to 0.10 seconds;
wider complexes may indicate bundle branch block or ventricular
origin.
9. Which type of lead is unipolar?
A. I, II, III
B. aVR, aVL, aVF, V1–V6
C. I, aVL, V1
D. II, III, aVF
Rationale: Unipolar leads measure electrical activity at one point
Certification Exam (NCET) Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which of the following best describes the function of an
electrocardiograph?
A. Measures blood pressure
B. Records the electrical activity of the heart
C. Measures oxygen saturation
D. Monitors brain waves
Rationale: The electrocardiograph (ECG) records the heart's electrical
impulses to detect arrhythmias, myocardial infarctions, and other
cardiac conditions.
,2. What is the standard speed at which ECG paper moves during a
recording?
A. 10 mm/sec
B. 20 mm/sec
C. 25 mm/sec
D. 50 mm/sec
Rationale: Standard ECG paper speed is 25 mm/sec, which allows
accurate interpretation of heart rate and waveform intervals.
3. Which lead is considered the "ground" lead in a standard 12-lead ECG?
A. RA (Right Arm)
B. LA (Left Arm)
C. LL (Left Leg)
D. RL (Right Leg)
Rationale: The right leg (RL) electrode serves as a ground to reduce
electrical interference in the ECG recording.
4. Which wave on an ECG represents atrial depolarization?
A. QRS complex
B. ST segment
C. P wave
D. T wave
, Rationale: The P wave corresponds to atrial depolarization, which
triggers atrial contraction.
5. Which interval represents the time between atrial and ventricular
depolarization?
A. PR interval
B. QT interval
C. PR segment
D. ST segment
Rationale: The PR segment is the flat line between the end of the P
wave and the start of the QRS complex, representing the conduction
delay through the AV node.
6. How many electrodes are used in a standard 12-lead ECG?
A. 6
B. 8
C. 10
D. 12
Rationale: A 12-lead ECG uses 10 electrodes: 4 limb electrodes and 6
chest electrodes to generate 12 views of the heart.
, 7. Which ECG change is commonly seen in hyperkalemia?
A. ST depression
B. Peaked T waves
C. Inverted P waves
D. Wide QRS with short PR
Rationale: Hyperkalemia can cause tall, peaked T waves due to
altered repolarization.
8. What is the normal duration of the QRS complex?
A. 0.04–0.06 sec
B. 0.06–0.10 sec
C. 0.10–0.14 sec
D. 0.14–0.20 sec
Rationale: A normal QRS duration ranges from 0.06 to 0.10 seconds;
wider complexes may indicate bundle branch block or ventricular
origin.
9. Which type of lead is unipolar?
A. I, II, III
B. aVR, aVL, aVF, V1–V6
C. I, aVL, V1
D. II, III, aVF
Rationale: Unipolar leads measure electrical activity at one point
