railway RRB JE (CBT I + CBT II) Mock Test 2024 Construction Materials and Management Building Component
As per IS standard specifications for timber door, window and ventilator frames, the symbolic designation of 12 DT 20 would indicate:
1
frame of window shutter door with a width of 12 modules and height of 20 modules
2
frame of ventilator with a width of 12 modules and height of 20 modules
3
frame of defined shutter door with a width of 12 modules and height of 20 modules
4
frame of double shutter door with a width of 12 modules and height of 20 modules