Match the Column-I with Column-II: Column-I (a) P-wave (b) QRS complex (c) T-wave (d) Reduction in the size of T-wave Column-II (i) Depolarisation of ventricles (ii) Repolarisation of ventricles (iii) Coronary ischemia (iv) Depolarisation of atria (v) Repolarisation of atria Select the correct option:
Answer: (A) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii). Answer: (a) (a)(iv) (b)(i) (c)(ii) (d)(iii) Solution: The P-wave is the depolarisation (electrical excitation) of the atria, so (a)-(iv).
- A.(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)✓
- B.(a)-(iv), (b)-(i), (c)-(ii), (d)-(v)
- C.(a)-(ii), (b)-(i), (c)-(v), (d)-(iii)
- D.(a)-(ii), (b)-(iii), (c)-(v), (d)-(iv)
Correct Answer
(A) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
Solution & Explanation
Answer: (a) (a)(iv) (b)(i) (c)(ii) (d)(iii) Solution: The P-wave is the depolarisation (electrical excitation) of the atria, so (a)-(iv). The QRS complex is the depolarisation of the ventricles, so (b)-(i). The T-wave is the return of the ventricles to normal, i.e. repolarisation of ventricles, so (c)-(ii). A reduced T-wave indicates the ventricular muscle is not getting enough oxygen, i.e. coronary ischemia, so (d)-(iii). This gives a-iv, b-i, c-ii, d-iii = option (a). NCERT: Ch 15, p.201, line 16 — "The QRS complex represents the depolarisation of the ventricles"