Question

Match List - I with List - II 

List - I (Defect)	List - II (Type)
A. Knot	III. Defects in timber
B. Dent and Buckles	II. Defects in plumbing (water supply)
C. Efflorescence	IV. Defects in brick due to presence of alkali
D. Dead spot	I. Acoustical defect

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

Hint:

Common construction defects:
• Knot $\rightarrow$ Timber defect
• Efflorescence $\rightarrow$ Alkali deposits on brick surfaces
• Dead Spot $\rightarrow$ Acoustical defect Efflorescence is usually seen as a white powdery deposit on masonry surfaces.

Answer 1

The Correct Option is B

Concept: Different defects occur in building materials and services due to material properties, environmental conditions, poor workmanship, or improper maintenance. Understanding these defects helps in identifying construction problems and selecting appropriate remedial measures.

Step 1: Match each defect with its type.
• A. Knot
Knots are common defects found in timber caused by the presence of branches in wood.
Therefore: \[ A \rightarrow III \]
• B. Dent and Buckles
Denting and buckling are defects occurring in plumbing or water supply pipelines due to improper handling or pressure conditions.
Therefore: \[ B \rightarrow II \]
• C. Efflorescence
Efflorescence is a defect in bricks caused by the presence of soluble alkalis that appear as white deposits on surfaces.
Therefore: \[ C \rightarrow IV \]
• D. Dead spot
A dead spot is an acoustical defect where sound intensity becomes very low due to sound wave interference.
Therefore: \[ D \rightarrow I \]

Step 2: Identify the correct combination.
Thus, the correct matching is: \[ A-III,\; B-II,\; C-IV,\; D-I \] Therefore, the correct answer is: \[ {A\text{-}III,\; B\text{-}II,\; C\text{-}IV,\; D\text{-}I} \]