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: . 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.
Electrocardiogram is a graphical representation of the cardiac cycle produced by an electrograph. The diagrammatic representation of a standard ECG is shown below.
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.
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:
Stay updated with our latest educational content and study tips
Interest is one of the most significant ideas in maths and financial calculations. It is very common in banking, loan applications, investments, saving account and competitive exams. Simple Interest and Compound Interest make it easier to find out how much more is earned and/or paid on a principal during the period of time. These Interest … Read more
Read MoreIn 2026, students, professionals, and job seekers must have a high level of spoken English. Spoken English is a beginner level course to enhance learners’ communication skills in English, their pronunciation, vocabulary, grammar structure and confidence in speaking English fluently. Today, the emphasis of spoken English courses is placed on actual conversations, everyday speech practice … Read more
Read MoreArtificial Intelligence (AI) and Machine Learning (ML) are two of the most sought-after technologies in today’s digital era. Although these terms are often used together, they are not the same. Machine Learning is, in fact, a component of Artificial Intelligence that enables systems to learn and enhance on their own, without direct programming. AI is … Read more
Read MoreTime, Speed, and Distance are some of the most important concepts in mathematics and aptitude. These are the concepts which are used to calculate the speed of an object, time taken for an object to move and the distance traveled during the motion. Questions from this topic are frequently seen in School Tests, Competitive Tests, … Read more
Read MoreWelcome 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.....
Comments
this is really very helpful to me ...thank you
It's brilliant
It was very long.
Acha to h but kaam nhi h
Goodd
Write a brief note on external respiration.