Ncert Exercises & Solutions

Which of the following correctly explains a phase/event in cardiac cycle in a standard electrocardiogram?

1. QRS complex indicates atrial contraction.

2. QRS complex indicates ventricular contraction.

3. Time between S and T represents atrial systole.

4. P-wave indicates beginning of ventricular contraction.

(b) QRS Complex QRS wave (complex) begins after a fraction of second after the P wave. It begins as a small downward deflection (Q) and continuous as a large upright (R) and triangular wave, ending as downward wave (S) at its base.

This represents ventricular depolarisation (ventricular contraction). Thus, the other options are wrong.

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions