Past Questions

A Planimetric map (or plan) is a representation of the Earth's surface that shows only the horizontal positions of features (such as roads, rivers, and buildings) without depicting relief or elevation (contours). These maps are often referred to as 'Chrographical maps' (from the Greek 'choros' meaning place/region and 'graphia' meaning writing/drawing), as they focus on the descriptive layout of a specific area's features on a flat plane. Why other options are incorrect: - a. Cadastral map: These are large-scale maps showing property boundaries and land ownership, specifically for legal and taxation purposes. - b. Wall map: This refers to the physical format/size of a map intended to be hung on a wall, not a specific cartographic type. - c. Atlas map: This refers to a collection of maps bound in a book, covering various scales and regions.

In Plane Table Surveying, the 'Two-Point Problem' and 'Three-Point Problem' are specific techniques used to establish the position of the table and align it with the map. 1. **Resection**: This is the process of determining the location of an unknown point (the station where the plane table is set up) by sighting known points on the ground whose positions are already plotted on the map. Both the two-point and three-point problems are primary methods of resection. 2. **Orientation**: Once the position of the table is fixed (resection), the table must be aligned so that the lines drawn on the paper are parallel to the corresponding lines on the ground. This process is called orientation. Since the ultimate goal of solving these problems is to first find the station's location (Resection) and then align the table (Orientation) to begin further plotting, these methods encompass both processes. While they are fundamentally resection methods, they are used specifically to achieve orientation of the map relative to the ground.

The fundamental principle of chain surveying is 'triangulation'. In this method, the area to be surveyed is divided into a network of well-conditioned triangles. This is done because a triangle is the only simple plane figure that can be uniquely defined by knowing the lengths of its three sides (SSS congruence). By measuring the lengths of the sides of these triangles using a chain or tape, the relative positions of all points in the survey area can be accurately plotted on a map. Why other options are incorrect: - a. Rectangle: A rectangle requires knowledge of angles (90 degrees) to be defined; chain surveying primarily relies on linear measurements. - b. Straight lines: While chains measure straight lines, a single line does not define an area. - d. Squares: Similar to rectangles, squares require specific angle measurements and equal side lengths, which is not the general principle used to divide an unknown terrain.

Magnetic dip (also known as magnetic inclination) is the angle that a magnetic needle makes with the horizontal plane of the earth. 1. At the Magnetic Equator: The magnetic field lines are parallel to the earth's surface, so the dip is 0°. 2. At the Magnetic Poles: The magnetic field lines are perpendicular to the earth's surface, pointing vertically downwards (at the North Pole) or upwards (at the South Pole). Therefore, the magnetic needle will stand vertically, making an angle of 90° with the horizontal plane. Comparing the options: - Option (a) 0° occurs at the magnetic equator. - Option (b) 45° occurs at some intermediate latitude between the equator and the poles. - Option (c) 60° occurs at some intermediate latitude. - Option (d) 90° occurs exactly at the magnetic poles.

An optical square is a instrument used in surveying to set out right angles (90 degrees) from a given line. It works on the principle of reflection. The instrument consists of a frame with a mirror fixed at an angle of 45° to the line of sight. When the surveyor looks through the eyepiece, they see a reflection of the object in the mirror. According to the laws of reflection, the angle between the incident ray (the line of sight to the mirror) and the reflected ray (the line of sight to the object) is twice the angle between the mirror and the line of sight. Since the mirror is fixed at 45°, the angle between the two lines of sight is 2 × 45° = 90°. Therefore, the mirror must be fixed at exactly 45° to ensure a precise right angle is established.

Surveying is defined as the art and science of determining the relative positions of points on, above, or beneath the surface of the earth by means of direct or indirect measurements of distance, direction, and elevation. The primary objective of these measurements is to represent the relative positions of these points on a plane surface (usually paper or a digital screen) to a suitable scale. This graphical representation is called a 'Map' or a 'Plan'. Why other options are incorrect: - a. Drawing: This is a general term. While a map is a type of drawing, 'Map' is the specific technical term used in surveying. - b. Cross-Section: A cross-section is a specific type of survey result used to show the profile of the ground perpendicular to a centerline (common in road or canal works), but it is not the overall object of surveying in general. - d. Model: A model is a three-dimensional representation. While 3D models (like BIM or Digital Terrain Models) exist, the fundamental and primary object of traditional surveying is the production of a map.

In surveying, there are two main types of surveying based on the consideration of the Earth's curvature: Plane Surveying and Geodetic Surveying. 1. Plane Surveying: In this method, the curvature of the earth is neglected, and the surface of the earth is treated as a plane. This assumption is acceptable for small areas where the error introduced by ignoring the curvature is negligible. 2. Geodetic Surveying: In this method, the curvature of the earth is taken into account. This is necessary for high-precision work and large areas. Standard surveying textbooks and engineering conventions establish that plane surveying is applicable for areas up to approximately 250 square kilometers. Beyond this limit, the spherical nature of the Earth becomes significant enough that the discrepancy between a plane and a sphere cannot be ignored, necessitating the use of geodetic methods. Therefore, for an area less than 250 sq km, plane surveying is the appropriate method.

An optical square is a instrument used in surveying to set out a right angle (90°) from a given line. It works on the principle of double reflection. It consists of two plane mirrors, one fixed and one movable, joined at an angle. According to the laws of reflection, the angle between the incident ray and the reflected ray is twice the angle between the two reflecting surfaces. To achieve a reflected ray that is perpendicular (90°) to the original line of sight, the mirrors must be set at an angle of 45° (since 2 × 45° = 90°). Therefore, the angle of intersection of the two plane mirrors in an optical square is 45°.

In Total Station surveying, there are two primary modes of distance measurement: Prism Mode and Reflectorless (Non-Prism) Mode. 1. **Prism Mode**: In this mode, the instrument emits an infrared signal that is reflected back by a glass prism. Because the prism is designed to reflect the signal with high efficiency, the signal strength remains strong over long distances. For standard professional-grade Total Stations used in land revenue and settlement surveys, the typical maximum range for prism mode is approximately 2km to 5km, depending on the instrument's specifications. Among the given options, 2km is the standard recognized upper limit for general-purpose Total Stations. 2. **Reflectorless Mode**: This mode measures distance by reflecting the signal off a surface (like a wall or rock). Because the reflection is diffuse and weak, the range is significantly shorter, typically between 100m to 1km. Comparing the options: - 500m (a) and 1km (b) are common limits for reflectorless modes or low-end equipment. - 1.5km (d) is a possible range but not the standard benchmark for the maximum capability of prism mode in technical examinations. - 2km (c) represents the standard operational range for most conventional Total Stations in prism mode.

The word 'Map' is derived from the Latin word 'Mappa', which literally means 'napkin' or 'cloth'. In ancient times, maps were often drawn on pieces of cloth or parchment, leading to the adoption of this term to describe a representation of an area of land or sea. - Option (a) Greek: While the Greeks contributed significantly to cartography (e.g., Ptolemy), the specific etymology of the word 'map' is not Greek. - Option (b) German: The word does not originate from Germanic languages. - Option (d) French: While French influenced many English words, 'map' traces back further to the Latin root.

The Global Positioning System (GPS), operated by the United States Space Force, is designed to maintain a minimum constellation of 24 operational satellites to ensure that at least four satellites are visible from any point on Earth at any time (which is the minimum required for a 3D position fix). While the actual number of satellites in orbit often exceeds 24 (due to spares and modernization efforts like GPS III), the standard theoretical and design baseline for the GPS constellation is 24 satellites, distributed across 6 orbital planes. In the context of competitive exams for surveying, '24' is the recognized standard answer for the baseline constellation size.

Plane Table Traversing is a method of surveying used to establish a series of connected stations. The principle involves setting up the plane table at a station, sighting a previous station to orient the table (back-sighting), and then sighting the next station to plot the line (fore-sighting). This process of establishing a sequence of lines by measuring directions and distances is fundamentally the same principle used in a Theodolite Traverse. In both cases, the surveyor establishes a framework of connected lines where the direction of each line is determined relative to the previous one. Why other options are incorrect: - a. Compass: While a compass measures bearings, a compass traverse relies on magnetic north, whereas plane table traversing relies on graphical orientation and sighting. - c. Radiation: Radiation is a specific method of plane table surveying used to locate points from a single station, not a method of traversing (which involves moving the instrument from station to station).

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 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.

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 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 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 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'.

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.