For a 2 m long cantilever beam with 1% Fe415 re-bars, the ratio of span to effective depth is .…

 

5)For a 2 m long cantilever beam with 1% Fe415 re-bars, the ratio of span to effective depth is .…

ans - 7 to 8 

Concept

For a cantilever beam with 1% Fe415 reinforcement as per IS 456:2000, the span-to-effective depth ratio is governed by the maximum permissible ratio for cantilever beams, which is typically specified in the code.

For cantilever beams, the ratio of the span to the effective depth is limited by IS 456:2000, Clause 23.2.2. For cantilever beams with 1% reinforcement, the maximum span-to-effective depth ratio is typically taken as 7 for cantilever beams.

Thus, for a cantilever beam of length 2 meters, the span-to-effective depth ratio ($l/d$) would be:

$$\frac{\text{Span}}{\text{Effective Depth}} = 7$$

So, the effective depth $d$ for the beam would be:

$$d = \frac{\text{Span}}{7} = \frac{2000 \, \text{mm}}{7} = 285.71 \, \text{mm}$$

Thus, the ratio of the span to effective depth is 7.