ANS:C - 176 cm

To find the breadth of the flange of the T-beam, we first need to calculate the clear span of the T-beam between the supporting beams. Then, we can determine the effective width of the flange based on the dimensions provided. Given:

• Clear cover: 13 cm
• Hall dimensions: 12 meters by 7 meters
• Spacing between adjoining beams: 3 meters
• Width of the T-beam: 20 cm

First, let's calculate the clear span of the T-beam between the supporting beams: The clear span of the T-beam will be equal to the distance between the two adjoining beams minus the clear cover on both sides. Clear span = Distance between beams - 2 * Clear cover The distance between the beams along the length of the hall is given by the hall width minus the spacing between the beams: Distance between beams = Hall width - Spacing between beams = 7 meters - 3 meters = 4 meters Now, let's calculate the clear span: Clear span = 4 meters - 2 * 13 cm = 4 meters - 26 cm = 4 meters - 0.26 meters = 3.74 meters Next, we can determine the effective width of the flange: Effective width of the flange = Width of T-beam - Clear cover on one side Effective width of the flange = 20 cm - 13 cm = 7 cm However, it seems there might be a mistake in the options provided. The calculated effective width of the flange is 7 cm, not in the range of the given options. It's possible that there might be a discrepancy in the question or the calculations. Please double-check the problem or provide additional information if needed.