Question

Match List-I with List-II (4-stroke petrol engine).

List-I	List-II
A. Inlet valve opens (IVO) B. Inlet valve closes (IVC) C. Exhaust valve opens (EVO) D. Exhaust valve closes (EVC)	I. 10°–15° after TDC II. 30°–40° after BDC III. 10°–20° before BDC IV. 30°–50° before BDC

• A. A-I, B-II, C-III, D-IV
• B. A-II, B-I, C-IV, D-III
• C. A-III, B-II, C-I, D-IV
• D. A-IV, B-I, C-II, D-III

Hint:

Valve timing always overlaps near TDC for better efficiency.

Answer 1

The Correct Option is A

Concept: Valve timing in IC engines ensures efficient breathing.

Step 1: Inlet valve opens (IVO).
Occurs slightly before TDC: \[ 10^\circ - 15^\circ \text{ before/after TDC} \Rightarrow A \rightarrow I \]

Step 2: Inlet valve closes (IVC).
Occurs after BDC: \[ 30^\circ - 40^\circ \text{ after BDC} \Rightarrow B \rightarrow II \]

Step 3: Exhaust valve opens (EVO).
Occurs before BDC: \[ 10^\circ - 20^\circ \text{ before BDC} \Rightarrow C \rightarrow III \]

Step 4: Exhaust valve closes (EVC).
Occurs after TDC or before: \[ 30^\circ - 50^\circ \Rightarrow D \rightarrow IV \]

Step 5: Final matching.
\[ A-I,\; B-II,\; C-III,\; D-IV \] \[ \boxed{\text{Answer: Option (1)}} \]