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Past Questions — 2023
Affinity law of the pump defines change in
A)
Pump Capacity
B)
Pump head
C)
Pump BHP
D)
All of above
The Affinity Laws for centrifugal pumps are a set of mathematical relationships used to predict the performance of a pump when there are changes in the impeller speed (RPM) or the impeller diameter. These laws define how the three primary performance parameters change:
1. Pump Capacity (Flow Rate, Q): The flow rate is directly proportional to the speed. (Q2/Q1 = N2/N1)
2. Pump Head (H): The head is proportional to the square of the speed. (H2/H1 = (N2/N1)²)
3. Pump Brake Horsepower (BHP/Power, P): The power required is proportional to the cube of the speed. (P2/P1 = (N2/N1)³)
Since the Affinity Laws define the changes in capacity, head, and power (BHP), all three options (a, b, and c) are correct.
Which line passes through true north and true south?
A)
True meridian
B)
Magnetic meridian
C)
Magnetic north
D)
Arbitrary meridian
In surveying, a meridian is a line that connects the North and South poles. There are three types of meridians used:
1. True Meridian: This is the line passing through the geographic North and South poles. It is fixed and does not change over time, making it the absolute reference for true north.
2. Magnetic Meridian: This is the line passing through the magnetic North and South poles. It is determined by a freely suspended magnetic needle and changes over time due to magnetic variation.
3. Arbitrary Meridian: This is a reference line chosen for convenience in a specific survey project when true or magnetic north is not required.
Since the question specifically asks for the line passing through true north and true south, the correct answer is the True Meridian.
A delay detonator has a delay element introduced between
A)
Primer charge and base charge
B)
Fuse head and primer charge
C)
Neoprene plug and neoprene sleeve
D)
Detonator tube and fuse head
A delay detonator is designed to create a specific time lag between the initiation of the fuse and the final detonation of the main explosive charge. The internal structure of a standard delay detonator consists of: 1. The Fuse Head (where the safety fuse is inserted), 2. The Delay Element (a slow-burning pyrotechnic composition), and 3. The Primer Charge (the primary explosive that triggers the base charge). The delay element is strategically placed between the fuse head and the primer charge so that the fire from the fuse must first burn through the delay composition before it can ignite the primer charge.
Analysis of other options:
- Option (a): The primer charge and base charge are both part of the detonating train; the delay happens before the primer is reached.
- Option (c): Neoprene plugs and sleeves are sealing components used to prevent moisture ingress, not timing elements.
- Option (d): The detonator tube is the outer shell; the fuse head is the entry point. The delay element is inside the tube, following the fuse head.
Variation in scale of photograph can take place due to variation in
A)
Elevation
B)
Azimuth
C)
Zenith
D)
Datum
In photogrammetry, the scale of a vertical aerial photograph is defined by the formula: Scale (S) = f / (H - h), where 'f' is the focal length of the camera, 'H' is the flying height above the datum (mean sea level), and 'h' is the elevation of the terrain above the datum. Since the focal length (f) and flying height (H) are generally constant for a specific flight line, any variation in the terrain elevation (h) directly causes a variation in the scale. Specifically, as the elevation (h) increases (e.g., a mountain top), the distance between the camera and the ground (H - h) decreases, resulting in a larger scale. Conversely, in valleys (lower elevation), the scale becomes smaller.
Other options are incorrect because:
- Azimuth (b) refers to the horizontal angle/direction of the flight line or a feature, which does not affect the magnification/scale.
- Zenith (c) refers to the point directly above the observer; while tilt (deviation from zenith) can cause scale variation across a photo, 'Zenith' itself is a reference point, not a variable causing scale change in the context of terrain.
- Datum (d) is the reference surface (like a geoid or ellipsoid) from which elevations are measured; changing the datum shifts the reference but does not cause local variation in the scale of a single photograph.
The alternate name of koepe winder is:
A)
Drum winder
B)
Multirope winder
C)
Friction winder
D)
Bi-cylindro winder
A Koepe winder is a type of hoist used in mining where the rope is not wound around a drum but instead passes over a drive pulley. The movement of the conveyance is achieved through the friction between the rope and the pulley (wheel). Therefore, it is widely known as a 'Friction Winder'.
Analysis of other options:
- a. Drum winder: In a drum winder, the rope is physically wound onto a rotating drum, which is the opposite mechanism of a Koepe winder.
- b. Multirope winder: While Koepe winders often use multiple ropes for safety and capacity, 'multirope' is a characteristic, not the alternate name for the system itself.
- d. Bi-cylindro winder: This refers to a specific type of drum winder using two cylinders to maintain constant rope tension, which is distinct from the friction-based Koepe system.
The laws of weight are established on the basis of
A)
Observed equation
B)
Normal equation
C)
Least square
D)
Probability equation
In surveying and geodesy, the 'laws of weight' are used to distribute discrepancies (errors) among several observations to find the most probable value of a quantity. These laws are fundamentally based on the 'Method of Least Squares'. The principle of least squares states that the most probable value of a quantity is that for which the sum of the squares of the weighted residuals (errors) is a minimum.
- Option (a) Observed equation: These are the equations derived from actual field measurements, but they do not establish the laws of weight.
- Option (b) Normal equation: These are the simplified equations derived from the least squares process to solve for unknowns, but they are a result of the method, not the basis of the laws of weight.
- Option (d) Probability equation: While the theory of probability underlies the distribution of errors, the specific mathematical framework used to establish weights and adjust observations in surveying is the Method of Least Squares.
What is the term generally applied to the operation of applying corrections to the latitudes and departures?
A)
Adjustment
B)
Closing error
C)
Traverse error
D)
Balancing
In surveying, specifically in traverse surveying, the sum of latitudes and departures of a closed traverse should theoretically be zero. However, due to measurement errors, a small discrepancy often exists, known as the 'closing error'. The process of distributing this error among the latitudes and departures of the traverse legs to make the traverse close mathematically is called 'Balancing'. Common methods for balancing include the Bowditch's rule (Compass rule) and the Transit rule.
Why other options are incorrect:
- a. Adjustment: While balancing is a form of adjustment, 'Adjustment' is a broad general term used in all types of surveying and engineering to refine measurements. 'Balancing' is the specific technical term for correcting latitudes and departures in a traverse.
- b. Closing error: This is the result of the inaccuracies (the gap between the starting and ending point), not the operation of applying corrections.
- c. Traverse error: This is a general term referring to any error occurring during the traverse process, not the specific operation of correcting the coordinates.
The voltage limit shall not exceed _________ for general lighting in underground metal mines.
A)
250 volts
B)
125 volts
C)
330 volts
D)
440 volts
In underground mining operations, safety regulations are extremely stringent to prevent electrical shocks and fires in confined, damp, or potentially hazardous environments. According to standard mining electrical safety regulations (such as those aligned with the CMR - Coal Mines Regulations or Metalliferous Mines Regulations), the voltage for general lighting in underground workings is restricted to a lower threshold to minimize the risk of fatal electric shock. The prescribed limit for general lighting in underground metal mines is typically 125 volts. This low-voltage requirement ensures that in the event of a fault or accidental contact, the potential for severe injury is significantly reduced compared to standard domestic or industrial voltages (like 230V or 440V). Options a, c, and d represent voltages that are too high for general underground lighting safety standards.
A tachometer differs from an ordinary theodolite in one respect that its diaphragm is fitted with
A)
Two additional vertical hairs
B)
Two additional horizontal hairs
C)
Three additional vertical hairs
D)
Three additional horizontal hairs
A tachometer is essentially a transit theodolite fitted with a stadia diaphragm. In an ordinary theodolite, the diaphragm typically contains only one horizontal cross-hair (the central hair) and one vertical hair for sighting and alignment. To perform tachymetric surveying (which allows for the determination of distance without a tape), two additional horizontal hairs—known as stadia hairs—are added. One is placed above the central hair and one below, usually at equal distances. By reading the interval between these two stadia hairs on a leveling staff, the distance to the object can be calculated using the stadia formula (D = ks + c). Therefore, the primary difference is the addition of two horizontal hairs.
GPS user solution depends on
A)
Absolute positioning
B)
Satellite vehicle
C)
Space vehicle
D)
Relative positioning
In the context of GPS (Global Positioning System) user solutions, there are two primary methods of positioning: Absolute (Point Positioning) and Relative (Differential Positioning). While absolute positioning provides a coordinate based on a single receiver, the 'user solution' in high-precision surveying and engineering (which is the context of a Civil Engineering/Surveying exam) typically refers to the ability to determine the position of a point relative to another known point to eliminate common errors (such as atmospheric delays and satellite clock errors). Relative positioning (Differential GPS) is the standard for professional surveying because it significantly increases accuracy. Therefore, the sophisticated 'user solution' for surveying depends on relative positioning. Options b and c (Satellite vehicle/Space vehicle) refer to the Space Segment of the GPS architecture, not the user solution method.
‘VOD’ is the property of
A)
detonator
B)
explosive
C)
electronic detonator
D)
cord relay
VOD stands for 'Velocity of Detonation'. It is a fundamental physical property of an explosive material that describes the speed at which the detonation wave travels through the explosive charge. VOD is critical in mining and blasting engineering because it determines the shattering effect (brisance) and the pressure exerted on the surrounding rock.
- Option (a) Detonator: A detonator is a device used to initiate the explosive; while it has a detonation rate, VOD is primarily used to characterize the main explosive charge.
- Option (c) Electronic detonator: This is a specific type of initiation system used for precision timing, not the material whose primary property is defined by VOD in a general blasting context.
- Option (d) Cord relay: This refers to the method of transmitting the detonation signal via detonating cord, which is a means of initiation rather than the explosive substance being characterized by its VOD for rock breakage.
The figure most commonly used in triangulation is a
A)
Quadrilateral with a centre point
B)
Quadrilateral with one diagonal
C)
Braced quadrilateral
D)
None of the above
In triangulation, the goal is to establish a network of triangles to determine the positions of points. While a simple triangle is the basic unit, larger networks are formed using quadrilaterals to increase accuracy and provide checks.
1. **Quadrilateral with a centre point**: This is used in some specific networks but is not the most common standard for general triangulation.
2. **Quadrilateral with one diagonal**: This effectively creates two triangles. While common, it lacks the redundancy required for high-precision surveying.
3. **Braced Quadrilateral**: A braced quadrilateral is a quadrilateral with both diagonals drawn. This configuration is the most commonly used figure in triangulation because it provides a high degree of internal check (redundancy). By measuring both diagonals, the surveyor can verify the accuracy of the angles and sides, ensuring that the network is geometrically sound and minimizing the propagation of errors.
Therefore, the 'braced quadrilateral' is the preferred figure for ensuring precision and reliability in triangulation networks.
The sound level of Audio Visual Alarm (AVA) should be at least _________ higher than ambient noise level as per the 10th National Safety Conference in Mines, 2007.
A)
2.0 – 10.0%
B)
4.0 – 6.0%
C)
5.0 – 20.0%
D)
none of the above
According to the guidelines established during the 10th National Safety Conference in Mines (2007) regarding Audio Visual Alarms (AVA) for mining machinery and safety systems, the sound level of the alarm must be significantly higher than the ambient noise level to ensure it is audible to operators and personnel. The standard requirement is that the alarm sound level should be at least 15 dB (decibels) higher than the ambient noise level. The options provided (a, b, and c) are expressed in percentages (%), which is an incorrect unit of measurement for sound level differences (which are measured in decibels, a logarithmic scale). Since none of the options provide the correct value of 15 dB or use the correct unit of measurement, the correct choice is 'none of the above'.
The biological oxygen demand (BOD) test is made for measuring
A)
Air pollution
B)
Water pollution
C)
Soil pollution
D)
All of the above
Biological Oxygen Demand (BOD) is a chemical procedure used to determine the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature over a specific time period.
1. Why it measures Water Pollution: High BOD levels indicate that there is a large amount of organic matter (such as sewage or agricultural runoff) in the water. As bacteria decompose this organic matter, they consume dissolved oxygen. If the BOD is too high, oxygen levels in the water drop, leading to the death of fish and other aquatic life (hypoxia).
2. Why other options are incorrect:
- Air pollution (a) is measured using indices like the Air Quality Index (AQI), measuring pollutants like PM2.5, PM10, NO2, and SO2.
- Soil pollution (c) is measured by analyzing the concentration of heavy metals, pesticides, or pH levels in soil samples.
- Since BOD is specific to the oxygen consumption in aqueous environments, 'All of the above' (d) is incorrect.
Which of the following is treated as base explosive?
A)
Gun powder
B)
Potassium nitrate
C)
NaCL
D)
TNT
In the context of explosives engineering and military applications, a 'base explosive' is a stable, high-explosive compound that serves as the primary ingredient or matrix for creating other explosive mixtures, boosters, or composite charges.
1. **TNT (Trinitrotoluene)**: It is the quintessential base explosive because of its high stability, low sensitivity to shock and friction, and its ability to be melted and cast into various shapes. It is frequently mixed with other materials (like RDX or PETN) to create more powerful explosives (e.g., Composition B).
2. **Gun powder (Option a)**: This is a low explosive (propellant) consisting of a mixture of sulfur, charcoal, and potassium nitrate. It is not used as a 'base' for high-explosive formulations.
3. **Potassium nitrate (Option b)**: This is an oxidizer, not an explosive on its own. While it is a component of gunpowder, it is a chemical precursor rather than a base explosive.
4. **NaCL (Option c)**: This is Sodium Chloride (common table salt), which is chemically inert in the context of explosives and has no explosive properties.
Identify the health effects of noise pollution in a mining complex.
A)
Speech interference
B)
Hearing loss
C)
Hypertensions
D)
All of the above
Noise pollution in a mining complex (caused by heavy machinery, drilling, blasting, and ventilation fans) has both auditory and non-auditory health effects:
1. **Speech Interference (Option a):** High ambient noise levels mask human speech, leading to communication failures. In a mining environment, this is a critical safety hazard as it prevents workers from hearing warnings or instructions.
2. **Hearing Loss (Option b):** Prolonged exposure to high decibel levels leads to Noise-Induced Hearing Loss (NIHL). This can be temporary (temporary threshold shift) or permanent (permanent threshold shift) due to the destruction of hair cells in the cochlea.
3. **Hypertension (Option c):** Noise acts as a physiological stressor. Chronic exposure triggers the body's stress response (activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis), which increases heart rate and leads to systemic hypertension (high blood pressure) and cardiovascular diseases.
Since all three options are documented health effects of noise pollution, the correct answer is 'All of the above'.
In solid blasting practice which of the following type of initiation is preferred?
A)
direct initiation
B)
middle initiation
C)
multiple initiation
D)
inverse initiation
In blasting practice, particularly in solid blasting (where the rock mass is competent and lacks natural fractures), the goal is to ensure maximum fragmentation and efficient energy distribution.
1. **Multiple Initiation**: This involves initiating the explosive charge at more than one point along the borehole. By using multiple primers or detonators, the detonation wave travels from multiple points simultaneously. This reduces the distance the detonation wave must travel through the explosive column, minimizes the risk of 'dead-pressing' (where the shockwave from one charge compresses an adjacent charge, preventing it from detonating), and ensures a more uniform distribution of energy throughout the rock mass, leading to better fragmentation.
2. **Direct Initiation**: This typically refers to initiating a charge directly with a detonator at one end. While common, it is less efficient than multiple initiation for large or critical solid blasts because it creates a single wave front that may lose energy or cause uneven breakage.
3. **Middle Initiation**: Initiating from the center is a specific form of initiation, but it is not the general 'preferred' practice compared to the flexibility of multiple initiation points.
4. **Inverse Initiation**: This is not a standard technical term used in conventional blasting initiation sequences.
Therefore, multiple initiation is preferred in solid blasting to optimize the breakage of hard, competent rock.
The voltage limit shall not exceed _________ for general lighting in opencast coal mines.
A)
125 volts
B)
250 volts
C)
440 volts
D)
330 volts
According to the Coal Mines Regulations (CMR) and the associated safety standards for electrical installations in mines, specific voltage limits are prescribed to ensure the safety of personnel and prevent electrical hazards. For general lighting in opencast coal mines, the voltage is restricted to prevent high-voltage accidents in areas where workers are frequently present. The standard safety limit for general lighting circuits in such environments is typically capped at 250 volts. Options a (125V) is too low for standard general lighting grids, while options c (440V) and d (330V) exceed the safety threshold for general-purpose lighting and would pose a significant risk of fatal electric shock.
Flying height in aerial photographic surveying refers to
A)
Upper portion of the exposure station
B)
Bottom of the exposure station
C)
Depression of the exposure station
D)
Elevation of the exposure station
In aerial photogrammetry, the 'exposure station' is the precise location of the camera's lens (the perspective center) at the exact moment the photograph is taken. The 'flying height' is defined as the vertical distance (elevation) of this exposure station above a specific reference datum, typically the mean sea level (MSL) or the ground surface.
- Option (a) and (b) are incorrect because the exposure station is a point in space, not a physical object with an 'upper' or 'bottom' portion.
- Option (c) is incorrect because 'depression' refers to an angle or a lowering of land, whereas flying height is a measure of altitude/elevation.
- Option (d) is correct because flying height is essentially the altitude or elevation of the camera's optical center at the time of exposure.
Which of the blasting technique is used for controlling overbreak to achieve stable final slope?
A)
Air-decking technique
B)
Highwall blasting technique
C)
Buffer blasting technique
D)
Deep hole blasting technique
In mining and quarrying, controlling 'overbreak' (the unintended breakage of rock beyond the design limit) is critical for maintaining the stability of the final slope or wall.
1. **Highwall Blasting Technique (Correct):** This refers to specialized blasting methods (such as pre-splitting or smooth blasting) specifically designed to create a clean, stable fracture plane along the final limit of the excavation. By controlling the energy release, it minimizes damage to the remaining rock mass, thereby reducing overbreak and ensuring a stable final slope.
2. **Air-decking technique (Incorrect):** This involves leaving air gaps in the explosive column to reduce the powder factor and cost, or to modify the shockwave. While it can reduce overall vibration, it is not the primary technique for defining a stable final slope wall.
3. **Buffer blasting technique (Incorrect):** Buffer blasting is a transitional step between the main production blast and the final wall blast. While it helps protect the final wall, the 'Highwall blasting' category encompasses the overall strategy and specific techniques (like pre-splitting) used to achieve the final stable slope.
4. **Deep hole blasting technique (Incorrect):** This is a general method of blasting used for large-scale production where holes are drilled deep into the bench. It is focused on volume and fragmentation rather than the precision required to control overbreak at the final wall.
Find correction for refraction for a distance of 1200 m
A)
0.0106 m
B)
0.0160 m
C)
0.0016 m
D)
0.1600 m
Option B is correct: 0.0160 m.
A spur gear system has two gears of 26 and 37 teeth of module 4. What is the centre distance in mm between the driving and driven shaft of the spur gear?
A)
126
B)
136
C)
146
D)
156
To find the center distance between two spur gears, we use the following steps:
1. **Identify given values:**
- Number of teeth on gear 1 ($T_1$) = 26
- Number of teeth on gear 2 ($T_2$) = 37
- Module ($m$) = 4 mm
2. **Calculate the Pitch Circle Diameter (PCD) for each gear:**
The formula for the pitch circle diameter is $D = m \times T$.
- Diameter of gear 1 ($D_1$) = $4 \times 26 = 104$ mm
- Diameter of gear 2 ($D_2$) = $4 \times 37 = 148$ mm
3. **Calculate the Center Distance ($C$):**
The center distance for two externally meshing spur gears is the sum of their pitch radii, or half the sum of their pitch diameters:
$C = \frac{D_1 + D_2}{2}$
$C = \frac{104 + 148}{2}$
$C = \frac{252}{2}$
$C = 126$ mm
Alternatively, the formula can be written as $C = \frac{m(T_1 + T_2)}{2}$:
$C = \frac{4(26 + 37)}{2} = 2 \times 63 = 126$ mm.
Comparing this result to the options:
- Option (a) 126 is correct.
- Options (b), (c), and (d) are incorrect as they do not match the calculated value.
The minimum angle for gravity haulage is
A)
14o
B)
15o
C)
16o
D)
17o
Gravity haulage is a method of transporting tubs or cars down a gradient where the force of gravity is used to move the loaded vehicles. For gravity haulage to be effective and sustainable, the gradient must be steep enough to overcome the rolling resistance (friction) of the wheels and the rails. In mining engineering standards, the minimum gradient required to ensure that a loaded tub will move under its own weight (gravity) is generally accepted as 1 in 4 or approximately 15 degrees. If the angle is less than 15 degrees, the friction may be too high to allow the tubs to accelerate sufficiently or maintain movement, necessitating external power. Therefore, 15 degrees is the standard minimum angle cited in mining transport textbooks for gravity-based systems.
High angle conveyors are designed for steep gradient up to
A)
50°
B)
60°
C)
65°
D)
70°
Standard belt conveyors are limited to gradients of about 15° to 20° because the material will slide back due to gravity. High Angle Conveyors (HACs), also known as Sandwich Belt Conveyors or Cleated Belt Conveyors, are specifically engineered to transport bulk materials at much steeper inclinations. In mining and industrial applications, HACs are designed to handle gradients significantly higher than standard conveyors, typically ranging from 30° up to 90° (vertical). Among the given options, 70° represents a standard upper-limit design capability for many high-angle conveyor systems used in mining to reduce the footprint of the transport system. While some specialized systems can go to 90°, in the context of typical competitive exam technical specifications for 'high angle' design limits in mining transport, 70° is the recognized benchmark for steep gradient design among the provided choices.
Which of the following is not a method of levelling
A)
Barometric levelling
B)
Trigonometric levelling
C)
Traverse levelling
D)
Spirit levelling
Levelling is the branch of surveying used to determine the relative heights (elevations) of points on the earth's surface.
1. **Spirit Levelling (Option d):** This is the most common and accurate method of levelling. It uses a spirit level (bubble tube) to establish a horizontal line of sight to determine height differences using a levelling staff.
2. **Trigonometric Levelling (Option b):** This method determines the difference in elevation between two points by measuring the vertical angle (using a theodolite) and the horizontal distance between the points, applying trigonometric functions (tan θ = height/distance).
3. **Barometric Levelling (Option a):** This method estimates elevation based on the change in atmospheric pressure. Since pressure decreases as altitude increases, a barometer can be used to find the approximate height of a point relative to a known datum.
4. **Traverse Levelling (Option c):** This is not a recognized method of levelling. 'Traversing' is a method of horizontal surveying used to establish the relative positions of points (coordinates) by measuring distances and angles. While a traverse can be combined with levelling to create a 3D survey, 'Traverse levelling' itself is not a distinct method for determining elevation.