NWCA CET TEST EXAM QUESTIONS AND
CORRECT ANSWERS WITH RATIONALES
GRADED A+ LATEST UPDATE 2026
NWCA CET TEST QUESTIONS AND ANSWERS — FULLY SOLVED
1. Which structure prevents backflow from the right ventricle to the right
atrium?
Answer: Tricuspid valve
Rationale: The tricuspid valve closes during ventricular contraction to prevent
blood from returning to the atrium.
2. Which part of the conduction system initiates the heartbeat?
Answer: SA node
Rationale: The sinoatrial node acts as the natural pacemaker, generating impulses
that initiate each cardiac cycle.
3. What is the normal duration of the QRS complex?
Answer: 0.06–0.12 seconds
Rationale: QRS represents ventricular depolarization; duration beyond 0.12
seconds suggests bundle branch block or ventricular conduction delay.
,4. Which wave on the ECG represents atrial depolarization?
Answer: P wave
Rationale: The P wave corresponds to electrical activity in the atria before
contraction.
5. Which leads are considered inferior leads?
Answer: II, III, aVF
Rationale: These leads view the inferior surface of the heart, supplied by the right
coronary artery.
6. What does ST-segment elevation indicate?
Answer: Myocardial injury or infarction
Rationale: Elevation above baseline is a key sign of acute MI.
7. The PR interval represents?
Answer: Time from atrial depolarization to ventricular depolarization
Rationale: PR interval measures conduction through AV node and bundle of His.
8. Normal PR interval duration?
Answer: 0.12–0.20 seconds
Rationale: Values outside this range indicate first-degree AV block (<0.12 may
indicate accessory pathway).
,9. Which rhythm originates from the AV node?
Answer: Junctional rhythm
Rationale: Junctional pacemakers fire when SA node fails, producing P waves
inverted, absent, or after QRS.
10. What is preload?
Answer: Stretch of ventricles before contraction
Rationale: Preload depends on venous return; excessive preload may worsen heart
failure.
11. What is afterload?
Answer: Resistance ventricles must overcome to eject blood
Rationale: High afterload increases cardiac workload and oxygen demand.
12. Which ECG finding suggests hyperkalemia?
Answer: Tall, peaked T waves
Rationale: Elevated potassium affects repolarization, producing characteristic T
wave changes.
, 13. Which ECG finding suggests hypokalemia?
Answer: Flattened T waves, U waves
Rationale: Low potassium prolongs repolarization and can predispose to
arrhythmias.
14. What is the hallmark ECG finding in atrial fibrillation?
Answer: No distinct P waves, irregular R-R intervals
Rationale: Chaotic atrial activity causes irregular ventricular response.
15. Which heart sound is associated with ventricular filling?
Answer: S3
Rationale: S3 occurs during early diastole; may indicate volume overload or heart
failure in adults.
16. Which heart sound occurs during rapid ventricular ejection?
Answer: S1
Rationale: Closure of AV valves produces S1 at beginning of systole.
17. What is a common cause of wandering baseline on ECG?
Answer: Poor electrode contact or patient movement
Rationale: Electrode displacement and motion artifacts shift the baseline.
CORRECT ANSWERS WITH RATIONALES
GRADED A+ LATEST UPDATE 2026
NWCA CET TEST QUESTIONS AND ANSWERS — FULLY SOLVED
1. Which structure prevents backflow from the right ventricle to the right
atrium?
Answer: Tricuspid valve
Rationale: The tricuspid valve closes during ventricular contraction to prevent
blood from returning to the atrium.
2. Which part of the conduction system initiates the heartbeat?
Answer: SA node
Rationale: The sinoatrial node acts as the natural pacemaker, generating impulses
that initiate each cardiac cycle.
3. What is the normal duration of the QRS complex?
Answer: 0.06–0.12 seconds
Rationale: QRS represents ventricular depolarization; duration beyond 0.12
seconds suggests bundle branch block or ventricular conduction delay.
,4. Which wave on the ECG represents atrial depolarization?
Answer: P wave
Rationale: The P wave corresponds to electrical activity in the atria before
contraction.
5. Which leads are considered inferior leads?
Answer: II, III, aVF
Rationale: These leads view the inferior surface of the heart, supplied by the right
coronary artery.
6. What does ST-segment elevation indicate?
Answer: Myocardial injury or infarction
Rationale: Elevation above baseline is a key sign of acute MI.
7. The PR interval represents?
Answer: Time from atrial depolarization to ventricular depolarization
Rationale: PR interval measures conduction through AV node and bundle of His.
8. Normal PR interval duration?
Answer: 0.12–0.20 seconds
Rationale: Values outside this range indicate first-degree AV block (<0.12 may
indicate accessory pathway).
,9. Which rhythm originates from the AV node?
Answer: Junctional rhythm
Rationale: Junctional pacemakers fire when SA node fails, producing P waves
inverted, absent, or after QRS.
10. What is preload?
Answer: Stretch of ventricles before contraction
Rationale: Preload depends on venous return; excessive preload may worsen heart
failure.
11. What is afterload?
Answer: Resistance ventricles must overcome to eject blood
Rationale: High afterload increases cardiac workload and oxygen demand.
12. Which ECG finding suggests hyperkalemia?
Answer: Tall, peaked T waves
Rationale: Elevated potassium affects repolarization, producing characteristic T
wave changes.
, 13. Which ECG finding suggests hypokalemia?
Answer: Flattened T waves, U waves
Rationale: Low potassium prolongs repolarization and can predispose to
arrhythmias.
14. What is the hallmark ECG finding in atrial fibrillation?
Answer: No distinct P waves, irregular R-R intervals
Rationale: Chaotic atrial activity causes irregular ventricular response.
15. Which heart sound is associated with ventricular filling?
Answer: S3
Rationale: S3 occurs during early diastole; may indicate volume overload or heart
failure in adults.
16. Which heart sound occurs during rapid ventricular ejection?
Answer: S1
Rationale: Closure of AV valves produces S1 at beginning of systole.
17. What is a common cause of wandering baseline on ECG?
Answer: Poor electrode contact or patient movement
Rationale: Electrode displacement and motion artifacts shift the baseline.
