Legal Metrology • 2010 • Paper-I
Moist curing of the exposed surfaces of concrete is done for at least
A)
7 days
B)
10 days
C)
12 days
D)
14 days
Curing is the process of maintaining satisfactory moisture content and temperature in concrete to allow the hydration of cement to continue, ensuring the concrete reaches its intended strength and durability. According to standard engineering practices and codes (such as IS 456:2000 in the Indian context, which governs RCC in Mizoram), the minimum period for moist curing of concrete surfaces is generally specified as 7 days for ordinary Portland cement (OPC) in most environmental conditions. While curing periods can be extended to 10 or 14 days for specific conditions (like high-strength concrete, extreme weather, or when using mineral admixtures like fly ash/GGBS), the baseline 'at least' requirement for standard exposed surfaces is 7 days. Therefore, option (a) is the most appropriate answer for a general technical examination question.
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
A column slice is used to increase
A)
length of the column
B)
strength of the column
C)
cross sectional area of column
D)
none of the above
In steel structure design, a 'column splice' (often misspelled as 'slice' in some exam papers) is a method used to join two sections of a column together to form a continuous member. While the primary purpose of splicing is to achieve the required total length of the column, the engineering objective of a properly designed splice is to ensure that the joint can transfer the full load from the upper section to the lower section without failure. By effectively joining the members, the splice maintains the structural integrity and the overall load-carrying capacity (strength) of the column over its entire height.
Analysis of options:
- (a) Length of the column: Splicing is a means to achieve length, but the 'splice' itself is a connection detail, not a method to 'increase' length in a functional sense (you add more steel for length; the splice just connects them).
- (b) Strength of the column: The splice is designed to ensure the joint is as strong as the member itself, thereby ensuring the overall strength of the composite column.
- (c) Cross sectional area: Splicing does not increase the cross-sectional area; that would require using a larger section or adding plates (reinforcement).
Note: In the context of technical exams, 'splice' is the intended term. The splice ensures the continuity of strength across the joint.
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.
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 letter of congratulations to a friend on his/her getting an appointment for a new job.
Legal Metrology • Physics Paper-III
The fact that the electron cannot exist inside the nucleus is due to
A)
Pauli’s exclusion principle
B)
Quantization of energy
C)
Heisenberg’s uncertainty principle
D)
Ehrenfest theorem
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is 'Pauli’s exclusion principle' (Option A).
Legal Metrology • Physics Paper-III
For unitary matrix
A)
A A^T = I
B)
A = A^*
C)
A = A^T
D)
A A^* = I
A unitary matrix satisfies AA* = I, where * denotes conjugate transpose.
Legal Metrology • Physics Paper-III
In central force between two bodies, the magnitude of the force depends only on
A)
Distance between the two bodies and velocity of the bodies
B)
Distance between the two bodies
C)
Velocity of the two bodies
D)
Distance between the two bodies and angles
A central-force magnitude depends only on the separation r (for a conservative central force); among the options B is correct.
Legal Metrology • Physics Paper-III
Which of the following logic gate can be used to construct all the other logic gates?
A)
AND
B)
OR
C)
NOT
D)
NAND
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'OR' (Option B).
Legal Metrology • Physics Paper-III
Which of the following is a correct statement for a zener diode?
A)
Beyond breakdown voltage the diode current is almost constant
B)
Beyond breakdown voltage the voltage difference across the diode is almost constant
C)
Zener diode will be damaged if operated beyond the breakdown voltage
D)
The forward bias characteristic of a zener diode is different from an ordinary diode
In the breakdown region, the voltage across a Zener diode remains nearly constant over a wide range of currents.
Legal Metrology • Physics Paper-III
For any matrix A, the matrix B = A + A^* is always
A)
Hermitian
B)
Symmetric
C)
Singular
D)
Skew-symmetric
A+A* is always Hermitian because (A+A*)*=A*+A=A+A*.
Legal Metrology • Physics Paper-III
For Skew-Hermitian matrices
A)
A A^* = I
B)
A = A^*
C)
A = -A^*
D)
A = A^T
Skew-Hermitian matrices satisfy A=−A*.
Legal Metrology • Physics Paper-III
For orthogonal matrix
A)
A A^T = I
B)
A = A^T
C)
A = A^-1
D)
A = A^*
An orthogonal matrix satisfies AAᵀ=I; equivalently A⁻¹=Aᵀ.
Legal Metrology • Physics Paper-III
What causes the formation of depletion region in a pn junction?
A)
Diffusion of conduction electrons from the n-type semiconductor to the p-type semiconductor
B)
Diffusion of holes from the n-type semiconductor to the p-type semiconductor
C)
Diffusion of conduction electrons from the p-type semiconductor to the n-type semiconductor
D)
Temperature difference across the pn junction
The depletion region starts with diffusion of majority carriers across the junction, leaving fixed ions behind.
Legal Metrology • Physics Paper-III
The matrix [[0, 1], [-1, 0]] is a
A)
Singular matrix
B)
Skew-symmetric matrix
C)
Hermitian matrix
D)
Diagonal matrix
Aᵀ=−A for the given matrix, so it is skew-symmetric.
Legal Metrology • Physics Paper-III
Which of the following is an odd function?
A)
f(x) = a + cos x
B)
f(x) = 9
C)
f(x) = ax^2
D)
f(x) = x
f(x)=x satisfies f(−x)=−f(x), so it is odd.
Legal Metrology • Physics Paper-III
A UJT exhibit negative resistance when
A)
Current is less than valley current
B)
Current is less than peak current
C)
Current is more than peak current but less than valley current
D)
Current is zero
Based on established principles in Electrical / Electronics Engineering, the correct and most clinically/technically appropriate choice is 'Current is more than peak current but less than valley current' (Option C).
Legal Metrology • Physics Paper-III
Which of the following can be explained by classical physics?
A)
Interference of light
B)
Stability of atoms
C)
Photoelectric effect
D)
Spectrum of blackbody radiation
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is 'Stability of atoms' (Option B).
Legal Metrology • Physics Paper-III
The transpose of A = [[1, 3], [2, 0], [3, 4]] is
A)
Option A
B)
Option B
C)
Option C
D)
Option D
In the context of Quantitative Aptitude, the most appropriate and technically accurate answer is 'Option A' (Option A).
Legal Metrology • Physics Paper-III
The determinant of the matrix B = [[1, 2], [3, 4]] is
A)
11
B)
8
C)
2
D)
0
In the context of Quantitative Aptitude, the most appropriate and technically accurate answer is '8' (Option B).
Legal Metrology • Physics Paper-III
A is a symmetric matrix if
A)
A - A^T = 0
B)
A + A^T = 0
C)
A - A^* = 0
D)
det A = 0
Symmetry means A=Aᵀ, equivalently A−Aᵀ=0.
Legal Metrology • Physics Paper-III
According to Kepler’s law, for planet orbiting the sun, the sun is
A)
Located at the center of the orbit
B)
Located at one foci of the orbit
C)
Located at both foci of the orbit
D)
Located along the semi-minor axis
According to Kepler's first law, planets orbit in an ellipse with the sun located at one of the foci.
Legal Metrology • Physics Paper-III
According to Planck’s radiation law
A)
All photons have the same energy
B)
Photons of larger wavelength have larger energy
C)
Photons of smaller frequency have smaller energy
D)
Photons of larger frequency have larger energy
In the context of Unmapped / long tail, the most appropriate and technically accurate answer is 'Photons of larger frequency have larger energy' (Option D).
Legal Metrology • Physics Paper-III
An ideal diode
A)
Behaves like a perfect conductor when reverse bias is applied to it
B)
Behaves like a perfect conductor when forward bias is applied to it
C)
Behaves like a perfect insulator when forward bias is applied to it
D)
Behaves like an open switch when forward bias is applied to it
An ideal forward-biased diode is a perfect short/conductor; reverse-biased it is an open circuit.
