D42 FACE THE CHALLENGE

Which retaining wall type is preferred for heights exceeding 15 meters?

• Cantilever wall
• Gravity wall
• Counterfort wall
• Buttressed wall

Answer explanation

Counterfort retaining walls are ideal for heights over 15 m due to their enhanced structural performance.

Which seasoning method uses soluble salt solution to reduce external cracks in timber?

• Water seasoning
• Boiling
• Salt seasoning
• Electrical seasoning

Answer explanation

Chemical or salt seasoning reduces external cracks by pre-conditioning timber from inside out.

Which is a disadvantage of having multiple railway gauges in a country?

• Reduced axle load
• Increase in train speed
• Passenger inconvenience
• Less maintenance

Answer explanation

Multiple gauges cause trans-shipment issues and inconvenience for passengers.

Which unit in a total station performs real-time correction for temperature and pressure?

• Display unit
• Reflector
• Microprocessor
• EDM

Answer explanation

Microprocessor applies real-time environmental corrections in total stations.

IS 2062 refers to which type of structural steel?

• Cold-formed steel
• Fusion weld quality steel
• High tensile steel
• Plain carbon steel

Answer explanation

IS 2062 covers hot rolled fusion-weld quality structural steels.

Minimum cover for reinforcement in footings directly resting on soil is:

• 25 mm
• 40 mm
• 50 mm
• 75 mm

Answer explanation

As per standards, a minimum cover of 50 mm is required for soil-resting footings.

Which type of line is used to represent symmetry in engineering drawings?

• Hidden line
• Center line
• Dimension line
• Cutting plane line

Answer explanation

Center lines are used to denote axes of symmetry.

Which defect is formed due to alternate wetting and drying of unseasoned timber?

• Wet rot
• Dry rot
• Heart rot
• Foxiness

Answer explanation

Wet rot is caused by repeated wetting and drying, especially in improperly seasoned wood.

Which element is added to low carbon steel to enhance both strength and toughness?

• Carbon
• Vanadium
• Sulphur
• Zinc

Answer explanation

Vanadium enhances both yield strength and toughness in low carbon steels.

What is the preferred method for folding drawing sheets to fit A4 size?

• Method 1 - 297x190
• Method 2 - 297x210
• Method 3 - 297x200
• Method 4 - 297x220

Answer explanation

Method 2 (297 x 210 mm) is used to fold drawings to A4 size.