$ECG$ records:

Consider the following statements with respect to $ECG$ [Electrocardiogram] and choose the correct answer.
Statement $I$ : '$P$' wave represents the depolarisation of ventricles.
Statement $II$ : '$T$' wave represents the repolarisation of ventricles.

Normal diastolic pressure in a young man is about (in $,\text{mm Hg}$)

In an $ECG$,the depolarization of atria is indicated by

Which of the following sentences is correct?
$I$. $ECG$ is of a great clinical significance.
$II$. Electrocardiograph is the machine used to obtain an electrocardiogram.
$III$. To obtain a standard $ECG$,a patient is connected to the machine with $3$ electrical leads (one to each wrist and to the left ankle).
$IV$. Normal activities of the heart are regulated intrinsically (auto-regulated by nodal tissue).
$V$. Electrocardiogram is the graphical representation of the electrical activity of the heart during a cardiac cycle.
Which of the following options contains all the correct statements?

$ECG$ is a graphical representation of the electrical activity of the heart during