Question

A __________ steel door consists of a frame, a drum and a shutter of thin Steel plates or Iron sheets of thickness about 1 mm.

(a) Revolving

(b) Swing

(c) Rotation

(d) Rolling

The question was asked by my school teacher while I was bunking the class.

My question is taken from Parts of Window topic in section Doors, Windows and Ventilators of Construction & Building Materials

Answer 1

Right answer is (d) Rolling

Easy explanation: The rolling Steel doors are sufficiently strong and as they can be easily rolled up at the top, they cause no obstruction to the floor as well as the opening. The Rolling doors are usually provided for the garage, showrooms, shops, factory buildings, etc.