Past Questions — 2024

In surveying, a 'metallic tape' specifically refers to tapes made from metals that offer high tensile strength and low elasticity to ensure accuracy over long distances. The most common material used for these tapes is steel. Steel tapes are preferred because they are more durable and less prone to stretching (elongation) compared to cloth or linen tapes. While 'metal' (option c) is a general category, 'steel' (option b) is the specific technical material used for standard metallic surveying tapes. Copper (option d) is too soft and heavy for this purpose, and cloth (option a) is used for non-metallic tapes.

In surveying, the horizontal angle measured from a reference meridian (such as the True North, Magnetic North, or an arbitrary Grid North) to a line is defined as the 'Bearing' of that line. The reference line from which the angle is measured is called the meridian. There are two main systems of bearings: Whole Circle Bearing (WCB), measured clockwise from North, and Quadrantal Bearing (QB), measured from North or South towards East or West. Why other options are incorrect: - a. Angular direction: This is a general term for any angle but not the specific technical term used for direction relative to a meridian. - c. Deviation: In surveying, deviation usually refers to the difference between the magnetic meridian and the true meridian (declination) or the error of a compass needle. - d. Inclination: This refers to the vertical angle of a line relative to the horizontal plane (slope), not the horizontal direction relative to a meridian.

In Total Station and EDM (Electronic Distance Measurement) instruments, the speed of the electromagnetic wave is affected by the atmospheric conditions (temperature and pressure). To calculate the corrected distance, a correction factor is applied based on the refractive index of air. The standard atmospheric pressure at sea level, which serves as the reference or 'pressure constant' for these calculations, is 1013.25 millibars (mb). In the context of the provided options, 1013 Mba (where Mba refers to millibars) is the standard value used as the baseline for atmospheric pressure corrections in surveying instruments. Options b, c, and d are incorrect as they do not represent the standard atmospheric pressure constant.

In theodolite surveying, adjustments are categorized into two types: Permanent and Temporary. 1. Permanent Adjustments: These are made to the internal components of the instrument to ensure the axes are mutually perpendicular. These are done by the manufacturer or a specialist and are not done at every station. 2. Temporary Adjustments: These are the operations performed every time the instrument is set up at a new survey station to make it ready for taking observations. These include: - Setting up: Placing the instrument over the station mark. - Centering: Ensuring the vertical axis of the instrument is exactly over the station point (using a plumb bob or optical plummet). - Leveling: Making the vertical axis truly vertical using leveling screws and the plate bubble. - Elimination of Parallax: Focusing the eyepiece and objective lens to ensure the cross-hairs and the object are in the same plane. Since these steps must be performed specifically at the point where the measurement is being taken, the temporary adjustment is done 'On the station'.

A physical map represents the natural features of the earth's surface, such as landforms, water bodies, and natural resources. 1. Mineral maps (Option a) show the distribution of natural mineral deposits in the earth's crust, which is a physical characteristic of the land. 2. Soil maps (Option c) represent the types and distribution of soil across a region, which is a physical/geological property of the earth's surface. 3. Vegetation maps (Option d) show the distribution of natural flora and forests, which are biological physical features of the landscape. 4. Astronomical maps (Option b), however, map celestial bodies (stars, planets, galaxies) and the space beyond the Earth's atmosphere. Since they do not represent the physical geography of the Earth, they do not fall under the category of 'Physical maps' in the context of terrestrial cartography.

In chain surveying, obstacles are classified based on whether they obstruct chaining, ranging, or both. 1. **Obstacles to Chaining only**: These are obstacles that prevent the physical measurement of distance with a chain but allow the surveyor to see through or over them to maintain a straight line (ranging). Examples include a river or a pond (you can see across it to range, but you cannot pull a chain through the water). 2. **Obstacles to Ranging only**: These are obstacles that prevent the surveyor from seeing the target point but allow the chain to be laid on the ground. An example is a hillock or a ridge (you can chain around the base or over it, but you cannot see the line of sight through the hill). 3. **Obstacles to both Chaining and Ranging**: These are opaque, solid structures that neither allow a chain to pass through them nor allow a line of sight to be established through them. A building is the classic example of such an obstacle. Comparing the options: - **River (a)** and **Lake (b)**: Obstruct chaining but not ranging. - **Hillock (c)**: Obstructs ranging but not necessarily chaining (depending on the path). - **Building (d)**: Obstructs both the physical path of the chain and the line of sight for ranging.

In the context of surveying instruments like the Total Station or Theodolite, the vertical axis is the axis about which the instrument rotates in a horizontal plane. While the primary vertical axis is the main axis of rotation, the 'Trunnion axis' (or horizontal axis) is the axis about which the telescope rotates vertically. However, in many technical exam contexts regarding the mechanical structure of the instrument's rotation and support, the term 'Trunnion' refers to the pivot points. Specifically, the Trunnion axis is perpendicular to the vertical axis. Wait, let's refine the technical definition: The vertical axis is the axis about which the instrument rotates horizontally. The Trunnion axis is the horizontal axis. However, among the given options (Sighting, Upper clamp, Lower clamp), options b, c, and d are clearly components or functions, not axes. 'Trunnion' is the only term relating to the axes of rotation of the instrument. In some specific terminology or simplified exam keys for this specific paper, 'Trunnion' is used to describe the axis system. Correction: Strictly speaking, the vertical axis is the axis of the instrument. The Trunnion axis is the horizontal axis. But since 'Sighting' is a process, and 'Clamps' are locking mechanisms, 'Trunnion' is the only viable technical term for an axis provided in the options.

In chain surveying, the 'base line' is the most important line because all other measurements are based on it; any error in the base line will propagate through the entire survey. Therefore, it must be measured with the highest possible precision. 1. **Invar Tape (Correct):** Invar is an alloy of steel and nickel with a very low coefficient of thermal expansion. This makes it the most accurate tool for measuring long base lines as it minimizes errors caused by temperature fluctuations. 2. **Steel Tape:** While more accurate than a chain or metallic tape, it is still subject to significant thermal expansion and contraction compared to Invar. 3. **Metallic Tape:** These are generally less precise than steel or Invar tapes and are used for ordinary measurements. 4. **Chain:** Chains are prone to sagging, stretching, and permanent deformation over time, making them unsuitable for the high-precision requirements of a base line.

In surveying, tapes are classified based on the material used for their construction. 1. **Steel Tapes (Metallic Tapes):** These are the most common type of metallic tapes. They are made of steel or steel alloy and are preferred for their durability and higher accuracy compared to cloth tapes. They are used for general engineering surveys. 2. **Invar Tapes:** While Invar (an alloy of nickel and steel) is also metallic, it is specifically categorized as an 'Invar tape' rather than a general 'metallic tape' because of its extremely low coefficient of thermal expansion. Invar tapes are used for high-precision baseline measurements, not general metallic taping. 3. **Cloth and Wire Tapes:** These are composite tapes. A cloth tape is non-metallic, and a cloth-wire tape is a hybrid. 4. **Nickel:** Pure nickel is not used to manufacture surveying tapes due to cost and physical properties. Therefore, when a question asks generally what 'metallic tapes' are made of in the context of standard surveying equipment, the correct answer is Steel.

The Global Positioning System (GPS), operated by the United States, is designed to provide global coverage. To ensure that at least four satellites are visible from any point on Earth at any time, the system utilizes a constellation of at least 24 satellites. These satellites are distributed evenly across 6 orbital planes (orbits). Each orbital plane is inclined at 55 degrees relative to the Earth's equator, and the planes are spaced 60 degrees apart. This configuration ensures optimal spatial geometry for precise trilateration. Therefore, 24 satellites divided by 6 orbits equals 4 satellites per orbital plane.

Plane Table Surveying is a unique method of surveying where the field observations and the plotting of the map are done simultaneously in the field. Unlike other methods where data is recorded in a field book and plotted later in an office, the plane table allows the surveyor to plot the points and lines directly on the drawing sheet while observing the ground. Why other options are incorrect: - a. Chain Surveying: This is a linear measurement method where data is recorded in a field book and plotted later in the office. - b. Compass Surveying: This involves measuring angles and distances; the data is recorded in a field book and plotted later. - d. Contour Surveying: This is a method used to determine the relief of the ground (elevation) and can be performed using various instruments (like levels or theodolites), but it is not defined as a 'graphical method of simultaneous plotting'.

In surveying, balancing a traverse is the process of distributing the closing error among the various legs of the traverse to ensure the figure closes mathematically. There are two primary methods used for balancing the latitudes and departures of a traverse: the Bowditch Rule (Compass Rule) and the Transit Rule. The Transit Rule is used specifically when the angular measurements are more precise than the linear measurements. Analyzing the options: - Option (a) 'Prismoldal Rule' (likely a typo for Prismoidal Rule) is used for calculating volumes of earthwork. - Option (b) 'Transit Rule' is a standard method for balancing a traverse. - Option (c) 'Trapezoidal rule' is used for calculating the area of an irregular boundary. - Option (d) 'Simpson’s Rule' is used for calculating the area of an irregular boundary with higher accuracy than the trapezoidal rule. Therefore, the Transit Rule is the only option related to traverse balancing.

In chain surveying, ranging rods are used to mark the positions of stations and to align the chain line between two points. For a ranging rod to be effective, it must be visible from a distance and stable enough to be held vertically. Standard surveying practice specifies that ranging rods are typically made of wood or metal, painted in alternate bands of red and white (or black and white), and have a length ranging from 2 meters to 3 meters. This height ensures that the rod is visible over tall grass or small obstacles while remaining portable and easy to handle for the surveyor. Options a, c, and d are incorrect as they either fall below the minimum visibility threshold or exceed the practical handling limit for standard ranging operations.

Step-by-step reasoning: 1. Definition: Leveling is a branch of surveying used to determine the relative heights (elevations) of points on the Earth's surface. 2. Process: It involves measuring vertical distances from a known reference point, called a 'datum' (such as Mean Sea Level or an arbitrarily assumed benchmark). 3. Analysis of options: (a) Leveling is the specific process of finding elevations. (b) Surveying is the broad umbrella term that includes leveling, chaining, and theodolite work. (c) Contouring is the process of drawing lines connecting points of equal elevation, which is a result of leveling, not the method of finding the elevation itself. (d) 'Level of surface' is a descriptive term, not a surveying process. Therefore, 'Leveling' is the precise technical term for the operation described.

Step-by-step analysis of the options: 1. **Sextant (Option c):** A sextant is a doubly reflecting instrument used primarily in navigation and surveying to measure the angular distance between two visible objects (e.g., the angle between a celestial body and the horizon). It is specifically designed for the measurement of angles. 2. **Geodimeter (Option a):** This is an electronic distance measurement (EDM) instrument that uses light waves (infrared) to measure the distance between two points. It is used for linear measurement, not angle measurement. 3. **Tellurometer (Option b):** This is an EDM instrument that uses microwave signals to measure long distances. Like the Geodimeter, it is used for distance measurement. 4. **Telescope (Option d):** While a telescope is a critical component of angle-measuring instruments (like the Theodolite or Transit), a telescope by itself is an optical device used for magnification and sighting of distant objects. It does not have the graduated scales required to measure an angle independently. Therefore, the only instrument listed specifically used for the measurement of angles is the Sextant.

In surveying and leveling, the vertical distance of a point above or below a fixed reference surface (called the datum) is defined by two interchangeable terms: 1. **Reduced Level (RL):** This is the technical term used in leveling to denote the vertical distance of a point relative to the datum. If the point is above the datum, the RL is positive; if below, it is negative. 2. **Elevation:** This is a general term used to describe the height of a point above a given reference level (usually Mean Sea Level, which serves as the global datum). Since both 'Reduced Level' and 'Elevation' refer to the same vertical distance from the datum, both options (a) and (b) are correct. Option (c) 'Height of the Instrument' is incorrect because it refers to the vertical distance from the datum to the line of sight (axis) of the leveling instrument, not the distance to the specific point being measured.

In theodolite surveying, reading both verniers (Vernier A and Vernier B) is a standard procedure used to eliminate errors related to the graduation of the circular scale. 1. **Graduation Error:** This occurs when the divisions on the main scale are not perfectly uniform or if there is a slight misalignment in the engraving of the scale. Since Vernier A and Vernier B are located 180 degrees apart on the circular scale, they read different parts of the scale for the same line of sight. By taking the average of the two readings, the graduation error is neutralized. 2. **Why other options are incorrect:** - **Personal Error:** These are caused by the observer (e.g., poor centering or parallax) and are reduced by careful practice and taking multiple readings, not specifically by using both verniers. - **Observation Error:** This is a general term for errors during the reading process; while reading both verniers helps verify the reading, it specifically targets the scale's physical graduation. - **Eccentricity Error:** This occurs when the axis of rotation of the instrument is not coincident with the center of the graduated circle. While reading both verniers helps in detecting eccentricity, the primary purpose of the dual-vernier system in standard theodolite operation is to eliminate graduation errors. (Note: In some advanced contexts, eccentricity is also mitigated, but 'Graduation' is the textbook answer for the primary purpose of reading both verniers in basic surveying).

In Chain Surveying, the field book is used to record measurements and sketches of the survey area. The standard size of a field book is generally 20 cm x 12 cm. It is opened lengthwise (longitudinally) so that the entries can be made from the bottom of the page upwards, mirroring the direction of the survey progress in the field. This allows the surveyor to easily plot the data later. Option (a) matches the standard technical specification used in surveying textbooks and practice. Options (b), (c), and (d) provide dimensions that do not conform to the standard industry size for a traditional surveying field book.

In Total Station surveying, there are two primary modes of distance measurement: Prism Mode and Non-Prism (Reflectorless) Mode. 1. **Prism Mode**: Uses a retro-reflector (prism) to bounce the signal back to the instrument. Because the prism is highly efficient, the range can be very long (often 3km to 5km). 2. **Non-Prism Mode**: The instrument measures the distance by reflecting the signal off a natural surface (like a wall or rock). Since natural surfaces are poor reflectors compared to prisms, the signal attenuates quickly, significantly limiting the range. While different manufacturers have different specifications, in the context of standard technical examinations for surveyors and common mid-range Total Stations (such as those frequently used in government land revenue departments), the standard rated range for reliable non-prism measurement is typically cited as 200 meters. Beyond this distance, the signal-to-noise ratio becomes too low for accurate measurement unless the target is highly reflective. Therefore, option (a) 200m is the most accurate standard answer for this technical specification.

In surveying, a standard metric chain (such as a 20m or 30m chain) is traditionally divided into 100 equal parts called 'links'. Step-by-step breakdown: 1. Total length of the chain = 20 meters. 2. Number of links = 100. 3. Length of one single link = Total Length / Number of links = 20m / 100 = 0.2m (or 20 cm). Comparing with options: - Option (a) 150 links: Incorrect. This is not a standard division for a metric chain. - Option (b) 100 links: Correct. This is the standard specification for a 20m metric chain. - Option (c) 200 links: Incorrect. - Option (d) 250 links: Incorrect.

The collimation method (also known as the Height of Instrument method) is a standard technique used in leveling to determine the reduced levels (RL) of various points. 1. **Differential Leveling:** This is the primary method used to find the difference in elevation between two points. The collimation method is frequently used here to calculate the RL of a new point based on a known benchmark. 2. **Profile Leveling:** This involves determining the elevations of points at measured intervals along a fixed line (like the centerline of a road or railway). The collimation method is the most efficient way to process these readings because the instrument remains in one position for multiple readings, allowing the surveyor to simply subtract staff readings from the established Height of Instrument (HI). 3. **Check Leveling:** This is a verification process (closing the loop) to ensure accuracy; while it uses the same calculations, it is a quality control step rather than a primary application of the method for data collection. Since the collimation method is fundamentally applicable to both profile and differential leveling, option (d) is the correct choice.

In leveling, a Bench Mark (BM) is a reference point of known elevation. There are different types of Bench Marks based on their permanence and purpose: 1. **Temporary BM (TBM):** This is a point whose elevation is established for a short period of time. It is typically used at the end of a day's work so that the leveling can be resumed from the same point the next day. It is not intended for long-term use. 2. **Arbitrary BM:** This is a point to which a convenient assumed elevation (e.g., 100.00 m) is assigned. It is used when the absolute elevation (Reduced Level) is not required, only the relative difference between points. 3. **GTS BM (Great Trigonometrical Survey BM):** These are permanent benchmarks established by national agencies (like the Survey of India) with high precision. They serve as the primary reference for all other leveling work in a region. 4. **Present BM:** This is not a standard technical term used in surveying to categorize types of benchmarks. Since the question specifically asks for the benchmark established at the end of a day's work to facilitate the continuation of the survey, the correct term is Temporary BM.

In surveying, the telescope of a leveling instrument contains a cross-hair system (reticle). The primary cross-hairs consist of one vertical hair and one central horizontal hair used for taking precise level readings on a staff. To enable the measurement of distances without a tape (a process called tachymetry or stadia leveling), two additional horizontal hairs are provided—one above and one below the central horizontal hair. These are known as 'Stadia hairs'. The distance between these two stadia hairs is constant (the stadia interval), and by multiplying the difference in readings between the upper and lower stadia hairs by a constant (usually 100), the horizontal distance to the staff can be calculated. Why other options are incorrect: - a. Focusing: This refers to the process or the knob used to make the image of the staff clear, not a physical hair in the reticle. - b. Diaphragm: This is the aperture or the circular opening that limits the light entering the telescope; it is not a hair. - c. Cross hair: While the stadia hairs are part of the cross-hair assembly, 'cross hair' generally refers to the primary central intersection used for leveling, whereas the question specifically asks for the 'two more' horizontal hairs.

In Plane Table Surveying, the 'Three Point Problem' (also known as the method of resection) is used to establish the position of the station where the plane table is set up by sighting three known points. There are two primary methods used to solve this problem: 1. The Graphical Method (also known as the Leibniz method): This involves drawing circles or arcs to find the intersection point. 2. The Analytical Method (also known as the Bessel method): This involves mathematical calculations using coordinates and trigonometry to determine the exact position of the station. Since there are two distinct approaches (Graphical and Analytical) to solve the three-point problem, the correct answer is 2.

An Alidade is a sighting device used in Plane Table Surveying. It consists of a straightedge (ruler) with an attached sighting mechanism (either a plain alidade with vanes or a telescopic alidade) used to draw lines of sight (rays) from the station to the object being plotted. Why other options are incorrect: - a. Tacheometry: Uses a Tacheometer (a transit theodolite equipped with stadia hairs) to measure distances and elevations. - c. Chaining: Uses chains, tapes, and arrows for linear measurements. - d. Compass surveying: Uses a Prismatic or Surveyor's compass to determine the magnetic bearing of lines.