Legal Metrology • 2010 • Paper-I
The inner part of timber log surrounding the pitch is called
A)
sapwood
B)
heart wood
C)
cambium layer
D)
none of the above
To understand the structure of a timber log, we look at the cross-section of a tree trunk from the center outwards:
1. **Pith**: The innermost central core of the stem.
2. **Heartwood**: The inner part of the timber log that surrounds the pith. It consists of older, non-functional xylem cells that are often filled with resins, tannins, and oils, making it darker, harder, and more durable than the outer layers.
3. **Sapwood**: The outer, lighter-colored layer of wood between the heartwood and the cambium. It is responsible for transporting water and minerals from the roots to the leaves.
4. **Cambium Layer**: A thin layer of living cells between the sapwood and the inner bark that produces new xylem and phloem.
Note: The question uses the term 'pitch', which is a common typographical error in technical exams for 'pith'. The part surrounding the pith is the heartwood.
Legal Metrology • 2010 • Paper-I
On steel structures, dead load is the weight of
A)
steel work
B)
material supported permanently
C)
material fastened to steel work
D)
All the above
In structural engineering, 'Dead Load' refers to the permanent, stationary loads that act on a structure throughout its entire life. For a steel structure, the dead load consists of:
1. The self-weight of the structural members themselves (the steel work), such as beams, columns, and trusses (Option a).
2. The weight of permanent components supported by the steel frame, such as concrete floor slabs, roofing sheets, and walls (Option b).
3. The weight of permanent fixtures and attachments fastened to the steel work, such as HVAC ducts, plumbing pipes, electrical conduits, and ceiling finishes (Option c).
Since all three categories represent permanent weights that do not change over time (unlike live loads or wind loads), they are all components of the dead load. Therefore, option 'd' is the correct answer.
Legal Metrology • 2010 • Paper-I
The most commonly used sections in lateral system to carry shear force in built up columns, are
A)
rolled steel flats
B)
rolled angles
C)
rolled channels
D)
all the above
In the design of built-up columns (especially those used in lateral force-resisting systems like braced frames), the primary members are often designed to carry axial loads, while the 'lacing' or 'battening' systems are used to hold the main components together. However, when considering the sections used specifically to carry shear forces or to act as the web of a built-up member in a lateral system, rolled channels are the most common choice. Channels provide a good balance of shear strength and ease of connection (bolting/welding) to the main chords of the built-up column. Rolled steel flats (Option a) lack the necessary stiffness and sectional area to carry significant shear in large built-up columns. Rolled angles (Option b) are typically used as lacing or for smaller bracing members rather than as the primary shear-carrying section of a built-up column. Rolled channels are preferred because their shape allows them to be oriented to resist shear efficiently while providing a flat surface for connections.
Legal Metrology • 2010 • Paper-I
According to Unwin’s formula, if t is the thickness of the plate in mm, nominal diameter of the rivet is
A)
d = 1.91t
B)
d = 1.91t2
C)
d = 1.91 sqrt(t)
D)
d = 2.91 sqrt(t)
Unwin's formula is an empirical relationship used in structural steel design to determine the nominal diameter of a rivet based on the thickness of the plate being joined. The formula is expressed as: d = 6 * sqrt(t), where 'd' is the diameter of the rivet and 't' is the thickness of the plate. However, this formula is based on the units of inches. When converted to metric units (millimeters), the constant changes. Specifically, if 't' is in mm and 'd' is in mm, the formula becomes d = 1.91 * sqrt(t).
Let's verify the options:
- Option (a) d = 1.91t: This is a linear relationship, which is incorrect for rivet sizing.
- Option (b) d = 1.91t²: This would lead to excessively large rivets for thick plates.
- Option (c) d = 1.91 sqrt(t): This is the correct metric form of Unwin's formula.
- Option (d) d = 2.91 sqrt(t): The constant 2.91 is incorrect.
Legal Metrology • 2010
Write a letter of congratulations to a friend on his/her getting an appointment for a new job.
Legal Metrology • 2010
Expand the following in not less than three times the original length: The test of a great book whether we want to read it only once…a really great book we want to read even more than the first time…..new meanings with every reading…if a person of education and taste does not care to read a book more than once then it is probably not worth much….but a single opinion not trustworthy….a great book is one read and enjoyed by many people over many generations.
Legal Metrology • 2010
Write a précis of the following passage, giving it an appropriate title: The great advantage of early rising is the good start it gives us in our day’s work. The early riser has done a large amount of work before other men have got out of bed. In the early morning, the mind is fresh and there are few sounds or other distractions; so the work done at that time is generally well done. In many cases, the early riser also finds time to take some exercise in the fresh morning air and this exercise fills him with a fund of energy that will last until the evening. By beginning so early he knows that he has plenty of time to do thoroughly all the work he can be expected to do, and is not tempted to hurry over any part of it. He gets to sleep several hours before midnight, at a time when sleep is most refreshing and after a night’s sound rest, rises early next morning in good health and spirits for the labour of a new day.
