Building Construction Multiple Choice Questions & Answers (MCQs) on “Door Frames – 1”.
1. The size of a door frame is determined after allowing a margin of __________ all-round.
a) 1 mm
b) 3 mm
c) 5 mm
d) 7 mm
Clarification: A door frame consists of horizontal and vertical members forming an enclosure. The size of a door frame is determined after allowing a margin of 5 mm to both the sides and the top of the door opening. This is one of the recommendations laid down by the Indian Standard.
2. Which of the following frames are used only for those residential buildings where more funds are available?
a) Timber frames
b) Aluminium frames
c) Steel frames
d) Stone frames
Clarification: Aluminium frames are used only for those residential buildings where more funds are available because of their large costs. Timber frames can be easily attacked by termites. Stone frames are used in villages where the stone of good quality in required size is available.
3. The cross-sectional area of the head and the post of a door frame is generally kept the same.
Clarification: The cross-sectional area of the head and the post of a door frame is generally kept the same. The top horizontal member of the door frame is known as the head while the vertical members are known as posts.
4. Which of the following statements about concrete frames is false?
a) They are replacing timber frames in urban areas
b) They cost less than timber frames
c) They cost more than timber frames
d) They are cheaper than iron frames
Clarification: Concrete frames are nowadays replacing timber frames in urban areas due to large costs of timber frames. Also, timber frames decay very readily. Concrete frames are cheaper than timber frames as well as than iron frames.
5. The thickness of a timber frame may vary between _______
a) 20-35 mm
b) 60-75 mm
c) 20-35 cm
d) 60-75 cm
Clarification: Depending upon the size of the door opening and the type of timber used, the thickness of a timber frame may vary between 60-75 mm. The same thickness is used for the horizontal and vertical members of the door frame.
6. The width of a timber door frame is _______ if the shutter is provided only to one side of the door.
a) 10 mm
b) 50 mm
c) 100 mm
d) 200 mm
Clarification: The width of a timber door frame is 100 mm if the shutter is provided only to one side of the door. This is the general case of a timber frame. However, if the shutter is provided to both the sides of the frame, then the width is taken 125-140 mm.
7. The width of rebating of the timber frame at its outer edge varies between ________
a) 12.5-15 mm
b) 2.5-13 mm
c) 8.1-9.2 mm
d) 18.5-20.5 mm
Clarification: The width of rebating of the timber frame at its outer edge varies between 12.5-15 mm. In this case, the depth is equal to the thickness of the shutter. However, the depth of rebating of the timber frame at its inner edge is equal to 10 mm.
8. Which of the following is not a type of joint between the head and the post of the timber frame?
a) Closed mortised and tenoned joint
b) Open and pin joint
c) Pin and tenoned joint
d) Dovetailed joint
Clarification: The various types of joints between the head and the post of the timber frame are – closed mortised and tenoned joint, pin and tenoned joint, and dovetailed joint. However, Indian Standard recommends a dovetail joint out of these three types.
9. Which of the following is an anti-termite solution?
Clarification: Aldrex is an anti-termite solution. It is added to coal tar which is then rubbed on all the parts of the timber frame which are in contact with the masonry. This prevents the timber from the attack of termites. Acetone is a volatile solution and hence is soaked by the wood which makes it ineffective against the attack of termites.
10. In the figure below, B represents ____________
Clarification: The above figure represents a door frame. In this figure, A represents the head, B represents post, C represents rebate and D represents holdfast. The post is the vertical member of a door frame. It is also known as the jamb.