Answer: electrical.
- A electrical
- B chemical
- C only mechanical
- D thermal
Correct answer: A. electrical
Explanation: An ECG traces the electrical impulses that drive each heartbeat.
A single ECG cycle: the P wave marks atrial depolarisation (contraction signal), the large QRS complex marks ventricular depolarisation, and the T wave marks ventricular repolarisation (recovery) before the next cycle begins.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.