Question

For a sleeper density of (n + 5) the number of sleepers required for constructing a Broad Gauge (B.G.) railway track of length 650 m is given by
1. 1000
2. 900
3. 800
4. 700

Answer 1

Correct Answer - Option 2 : 900

Concept

Sleeper density is denoted by (n + x)

These vary from (n+3) to (n+6)

Where ‘n’ is the length of one rail

Generally length of one rail (n) = 13 m (Need to remembered)

Calculation

Given,

 Length of rail = 650 m

 For BG track, length of rail = 13 m

 Number of rails \(= \frac{{650}}{{13}} = 50\) 

 Sleeper Density = n + 5

 Number of sleepers per rail length = 13 + 5 = 18

 So number of sleepers needed = Number of rails × Sleeper density

 = 50× 18 = 900 

 ∴ Number of sleepers need = 900