NEET Biology: Ecg Practice Questions
14 free multiple-choice questions on Ecg (Human Physiology) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. What is the interval that measures the time taken for the electrical impulse to travel from the atria to the ventricles?
Show answer & explanation
Correct answer: A — PR interval
The PR interval measures the time delay between the start of atrial depolarization (P wave) and the start of ventricular depolarization (QRS complex).
Q2. The T wave on the ECG corresponds to which phase of the cardiac cycle?
Show answer & explanation
Correct answer: C — Ventricular repolarization
The T wave represents the repolarization (relaxation) of the ventricles.
Q3. Which electrical event is primarily represented by the P wave in an ECG?
Show answer & explanation
Correct answer: A — Atrial depolarization
The P wave represents the electrical activation (depolarization) of the atria (upper chambers of the heart).
Q4. The T wave on an ECG is generally associated with which phase of the cardiac cycle?
Show answer & explanation
Correct answer: A — Repolarization
The T wave represents the repolarization (relaxation) phase of the ventricles after they have contracted.
Q5. The ST segment on the ECG trace corresponds to which phase of the cardiac cycle?
Show answer & explanation
Correct answer: C — Ventricular repolarization
The ST segment follows ventricular depolarization and precedes ventricular repolarization, reflecting the plateau phase of ventricular repolarization.
Q6. Which wave on the ECG corresponds to the depolarization of the ventricles (ventricular systole)?
Show answer & explanation
Correct answer: D — QRS complex
The QRS complex represents the rapid depolarization of the ventricles, which causes ventricular contraction (systole).
Q7. In the normal ECG cycle, which wave occurs first, indicating the start of the electrical impulse reaching the heart muscle?
Show answer & explanation
Correct answer: A — P wave
The P wave always occurs first, marking the initial depolarization of the atria, setting the rhythm for the cardiac cycle.
Q8. Which structure in the heart is the primary source for initiating the electrical impulse of the heartbeat?
Show answer & explanation
Correct answer: D — SA node
The Sinoatrial (SA) node, located in the right atrium, acts as the natural pacemaker of the heart, setting the rhythm.
Q9. Which electrical event is responsible for the contraction of the ventricles?
Show answer & explanation
Correct answer: D — QRS complex
Ventricular depolarization (represented by the QRS complex) triggers the electrical impulse that leads to ventricular contraction.
Q10. What does the overall frequency of the heartbeat, measured in beats per minute, represent on an ECG?
Show answer & explanation
Correct answer: B — The heart rate (rate of ventricular activity)
The rate of the ECG (Heart Rate) is determined by the frequency of the R-R intervals, which reflects the rate of ventricular contraction.
Q11. The P wave in an ECG waveform represents which phase of the cardiac cycle?
Show answer & explanation
Correct answer: B — Atrial depolarization
The P wave reflects the electrical depolarization of the atria (upper chambers) as they contract.
Q12. If the heart rate is measured in beats per minute (BPM), what does this measurement quantify in an ECG context?
Show answer & explanation
Correct answer: A — The frequency of electrical impulses
Heart rate is the frequency of the electrical impulses generated by the heart, measured in beats per minute.
Q13. The T wave on an ECG corresponds to which electrical event in the heart muscle?
Show answer & explanation
Correct answer: C — Ventricular repolarization
The T wave represents the repolarization (relaxation) of the ventricles, preparing them for the next heartbeat.
Q14. The P wave in an electrocardiogram (ECG) primarily represents which cardiac event?
Show answer & explanation
Correct answer: C — Atrial depolarization
The P wave reflects the electrical activation (depolarization) occurring in the atria, which precedes ventricular contraction.
Keep going — practice on Padhai Karlo
Padhai Karlo gives you unlimited NEET practice: chapter-wise questions, timed quizzes, and full mock tests with an All-India Rank — free to start.
Get the free Android app →