If depth of slab is 10 cm, width of web 30 cm, depth of web 50 cm, centre to centre distance of beams 3 m, effective span of beams 6 m, the effective flange width of the beam, is A. 200 cm B. 300 cm C. 150 cm D. 100 cm

The correct answer is C. 150 cm.

The effective flange width of a beam is the width of the flange that is effective in resisting bending moment. It is calculated as follows:

$b_e = \frac{b_f}{2} + \frac{d_w}{2}$

where:

• $b_e$ is the effective flange width
• $b_f$ is the flange width
• $d_w$ is the web depth

In this case, we have:

• $b_f = 30$ cm
• $d_w = 50$ cm

Therefore, the effective flange width is:

$b_e = \frac{30}{2} + \frac{50}{2} = 150$ cm

The other options are incorrect because they do not take into account the width of the web.