Correct option is A
Plate girder are typically used as long-span floor girders in buildings, as bridge girders, and as crane girders in industrial structures.
• Plate girders are at their most impressive in modern bridge construction where main spans of well over zoom are feasible, with corresponding cross-section depths, launched over the supports, in the range of 5-10 m.
• When moment resisting capacity of the plate girder has to be increased, flange cover plates are provided over flange angles. The moment of inertia and consequently the moment resisting capacity of the girder is increased considerably as the flange cover plates are at the greatest distance from neutral axis.
• The flange cover plates should not be thicker than the flange angles in riveted/bolted connections. Hence, if necessary more than oneplate may be required. It is preferred that all cover plates should have same or less thickness than flange angle.
