Question

Read the assertion and reason carefully to mark the correct option in question.

Assertion: $\text{ECG}$ is a graphical representation of the electrical activity of the heart during a cardiac cycle.

Reason: Each peak in the $\text{ECG}$ is identified with the letter from $P$ to $Q$

that indicates electrical activity of the heart.

• A. If both assertion and reason are false.
• B. If both assertion and reason are true but the reason is not the correct explanation of the assertion.
• C. If assertion is true but the reason is false.
• D. If both assertion and reason are true and the reason is the correct explanation of the assertion.

Answer 1

The correct option is C

If assertion is true but the reason is false.

Assertion-Reason relation

Electrocardiogram is a graphical representation of electrical current produced by the heart.



Hence, the given assertion- $“$ $\text{ECG}$ is a graphical representation of the electrical activity of the heart during a cardiac cycle $”$ is true.

Electrocardiogram is composed of three waves:

$\bullet$ $\text{P-wave:}$ It represents atrial depolarisation or contraction.

$\bullet$ $\text{QRS}:$ It represents ventricular depolarisation or contraction.

$\bullet$ $\text{T-wave:}$ It represents ventricular repolarisation or relaxation.

Hence, the given reason- $“$ Each peak in the $\text{ECG}$ is identified with the letter from $P$ to $Q$ that indicates electrical activity of the heart.$”$ is false.

Final Answer:

$\left(C\right)$ If assertion is true but the reason is false.