Draw a standard ECG and explain the diff | Class 11 Biology Chapter Body Fluids and Circulation, Body Fluids and Circulation NCERT Solutions

Current NCERT chapter

Academic session 2026-27, Chapter 15 in the current curriculum.

Welcome to the NCERT Solutions for Class 11 Biology - Chapter Body Fluids and Circulation. This page offers a step-by-step solution to the specific question from Exercise 1, Question 14: Draw a standard ECG and explain the different segments in it.. With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 14: Draw a standard ECG and explain the different segments in it.
Answer:

Electrocardiogram is a graphical representation of the cardiac cycle produced by an electrograph. The diagrammatic representation of a standard ECG is shown below.

                                     standard ECG

A typical human electrocardiogram has five waves – P, Q, R, S, and T. The P, R, and T-waves are above the base line and are known as positive waves. The Q and S-waves are below the base line and are known as negative waves. The P-wave is of atrial origin, while the Q, R, S, and T-waves are of ventricular origin. 

(a) The P-wave indicates atrial depolarisation. During this wave, the impulse of contraction is generated by the SA node. The PQ-wave represents atrial contraction.

(b) The QR-wave is preceded by ventricular contraction. It represents the spread of the impulse of contraction from the AV node to the wall of the ventricle. It leads to ventricular depolarisation.

(c) The RS-wave represents ventricular contraction of about 0.3 sec.

(d) The ST-wave represents ventricular relaxation of about 0.4 sec. During this phase, the ventricles relax and return to their normal state.

(e) The T-wave represents ventricular relaxation.


Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about Body Fluids and Circulation.
  • Review previous year question papers to get an idea of how such questions may be framed in exams.
  • Practice answering questions within the time limit to improve your speed and accuracy.
  • Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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Comments

  • vaishnavi bire
  • Dec 17, 2019

this is really very helpful to me ...thank you


  • Soumya
  • Nov 27, 2019

It's brilliant


  • Sagar Barman
  • Aug 27, 2019

It was very long.


  • Vinay
  • Mar 18, 2019

Acha to h but kaam nhi h


  • Anshul Patidar
  • Nov 21, 2018

Goodd


  • Vijay Hemanth
  • Sep 27, 2018

Write a brief note on external respiration.


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Welcome to the NCERT Solutions for Class 11 Biology - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 14: Draw a standard ECG and explain the different segments in it.....

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