EKG TECHNICIAN (CET) EXAM
BANK – COMPREHENSIVE EXAM
WITH ANSWERS AND RATIONALES
1. The normal automaticity (intrinsic rate) of the
sinoatrial (SA) node is:
A) 20-40 beats per minute
B) 40-60 beats per minute
C) 60-100 beats per minute
D) 100-150 beats per minute
Correct answer: C
Rationale: The SA node normally fires at 60-100 bpm
(intrinsic rate); AV node 40-60 bpm; Purkinje fibers
20-40 bpm.
2. Which lead is considered the "rhythm strip" lead
for continuous monitoring in most clinical settings?
A) Lead I
B) Lead II
C) Lead aVR
D) Lead V1
,Correct answer: B
Rationale: Lead II aligns with the cardiac axis,
providing the best view of P waves and QRS
complexes for rhythm analysis.
3. The P wave on an EKG represents:
A) Ventricular depolarization
B) Atrial depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct answer: B
Rationale: The P wave reflects atrial depolarization;
the QRS complex reflects ventricular depolarization;
the T wave reflects ventricular repolarization.
4. The QRS complex typically has a duration of:
A) 0.04-0.10 seconds (40-100 ms)
B) 0.12-0.20 seconds
C) 0.20-0.30 seconds
D) 0.30-0.40 seconds
Correct answer: A
,Rationale: Normal QRS duration is ≤0.10 seconds (2.5
small boxes at 25 mm/s). Prolongation >0.12 seconds
indicates intraventricular conduction delay.
5. The PR interval is measured from the beginning of
the P wave to the:
A) Beginning of the Q wave (or R wave if no Q)
B) End of the QRS complex
C) Peak of the T wave
D) Beginning of the ST segment
Correct answer: A
Rationale: The PR interval (normal 0.12-0.20 sec)
includes atrial depolarization and AV nodal delay.
6. A large box (5 mm) on EKG paper at standard
speed (25 mm/sec) represents:
A) 0.04 seconds
B) 0.20 seconds
C) 0.40 seconds
D) 1.00 second
Correct answer: B
Rationale: At 25 mm/sec, 1 small box (1 mm) = 0.04
sec; 1 large box (5 mm) = 0.20 sec.
, 7. Which of the following is the correct placement for
the V1 electrode?
A) Fourth intercostal space, right sternal border
B) Fourth intercostal space, left sternal border
C) Fifth intercostal space, midclavicular line
D) Fifth intercostal space, anterior axillary line
Correct answer: A
Rationale: V1 is at the 4th ICS, right sternal border;
V2 is 4th ICS, left sternal border; V4 is 5th ICS,
midclavicular line.
8. Which precordial lead is placed at the fifth
intercostal space, left midclavicular line?
A) V1
B) V2
C) V4
D) V6
Correct answer: C
Rationale: V4 is the landmark lead; V5 is anterior
axillary line; V6 is midaxillary line at same horizontal
level as V4.
BANK – COMPREHENSIVE EXAM
WITH ANSWERS AND RATIONALES
1. The normal automaticity (intrinsic rate) of the
sinoatrial (SA) node is:
A) 20-40 beats per minute
B) 40-60 beats per minute
C) 60-100 beats per minute
D) 100-150 beats per minute
Correct answer: C
Rationale: The SA node normally fires at 60-100 bpm
(intrinsic rate); AV node 40-60 bpm; Purkinje fibers
20-40 bpm.
2. Which lead is considered the "rhythm strip" lead
for continuous monitoring in most clinical settings?
A) Lead I
B) Lead II
C) Lead aVR
D) Lead V1
,Correct answer: B
Rationale: Lead II aligns with the cardiac axis,
providing the best view of P waves and QRS
complexes for rhythm analysis.
3. The P wave on an EKG represents:
A) Ventricular depolarization
B) Atrial depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct answer: B
Rationale: The P wave reflects atrial depolarization;
the QRS complex reflects ventricular depolarization;
the T wave reflects ventricular repolarization.
4. The QRS complex typically has a duration of:
A) 0.04-0.10 seconds (40-100 ms)
B) 0.12-0.20 seconds
C) 0.20-0.30 seconds
D) 0.30-0.40 seconds
Correct answer: A
,Rationale: Normal QRS duration is ≤0.10 seconds (2.5
small boxes at 25 mm/s). Prolongation >0.12 seconds
indicates intraventricular conduction delay.
5. The PR interval is measured from the beginning of
the P wave to the:
A) Beginning of the Q wave (or R wave if no Q)
B) End of the QRS complex
C) Peak of the T wave
D) Beginning of the ST segment
Correct answer: A
Rationale: The PR interval (normal 0.12-0.20 sec)
includes atrial depolarization and AV nodal delay.
6. A large box (5 mm) on EKG paper at standard
speed (25 mm/sec) represents:
A) 0.04 seconds
B) 0.20 seconds
C) 0.40 seconds
D) 1.00 second
Correct answer: B
Rationale: At 25 mm/sec, 1 small box (1 mm) = 0.04
sec; 1 large box (5 mm) = 0.20 sec.
, 7. Which of the following is the correct placement for
the V1 electrode?
A) Fourth intercostal space, right sternal border
B) Fourth intercostal space, left sternal border
C) Fifth intercostal space, midclavicular line
D) Fifth intercostal space, anterior axillary line
Correct answer: A
Rationale: V1 is at the 4th ICS, right sternal border;
V2 is 4th ICS, left sternal border; V4 is 5th ICS,
midclavicular line.
8. Which precordial lead is placed at the fifth
intercostal space, left midclavicular line?
A) V1
B) V2
C) V4
D) V6
Correct answer: C
Rationale: V4 is the landmark lead; V5 is anterior
axillary line; V6 is midaxillary line at same horizontal
level as V4.
