D63 CHECK YOUR LEVEL

In railways, which component connects two adjacent rails and allows for expansion and contraction?

• Bearing plate
• Fish plate
• Spike
• Chair

Answer explanation

Fish plates join two rails and accommodate expansion/contraction.

Which type of weld is also called a groove weld and connects plates end to end?

• Butt weld
• Fillet weld
• Plug weld
• Slot weld

Answer explanation

Butt welds (or groove welds) connect plates end to end.

What is the expression for throat thickness in a fillet weld of size 'S'?

• S
• 0.5S
• 0.707S
• 0.67S

Answer explanation

Throat thickness in fillet weld is 0.707 × size of weld (S).

The maximum permissible spacing of main reinforcement in a slab should not exceed:

• 2d
• 3d
• 4d
• Effective depth

Answer explanation

IS Code limits spacing to 3 times diameter of bar or least dimension of slab.

Which sleeper type has the highest life expectancy among all common types used in Indian Railways?

• Timber
• Concrete
• Cast iron
• Steel

Answer explanation

Cast iron sleepers have a lifespan of 60 years, more than other types.

According to Unwin’s formula, what is the rivet diameter for a 16 mm thick plate?

• d = 1.5t + 4
• d = 6.05√t
• d = √(50t - 2)
• d = t + 10

Answer explanation

Unwin’s formula: d = 6.05√t where t = thickness of plate.

Which type of slab is supported only on two opposite sides and bends primarily in one direction?

• Two-way slab
• Flat slab
• One-way slab
• Raft slab

Answer explanation

One-way slabs bend in one direction and are supported on two opposite sides.

In fluid mechanics, the majority of energy loss in pipe flow is due to:

• Minor losses
• Frictional loss
• Turbulence
• Sudden expansion

Answer explanation

Majority of losses are due to pipe-wall friction as per Darcy–Weisbach.

Which AutoCAD command is used to reduce objects in size proportionally with a reference point?

• REDUCE
• SCALE
• STRETCH
• SHRINK

Answer explanation

SCALE command is used for proportionate reduction/enlargement.

According to the Darcy–Weisbach equation, head loss due to friction is proportional to:

• flow velocity squared
• flow velocity
• pipe diameter
• pressure head

Answer explanation

Darcy–Weisbach formula includes velocity squared for head loss.