Controller of Mines • 2026 • Technical Paper-II
In a drum hoisting system through a vertical shaft, overwinding is prevented by:
A)
Lilly controller
B)
Detaching hook
C)
Caliper Brake
D)
Safety catch
In a drum hoisting system used in a vertical shaft, overwinding means the cage or skip rises too far and goes beyond the safe upper limit. This is prevented by a device called a Lilly controller, which acts as an overwind prevention and control mechanism. A detaching hook is used mainly in cage safety arrangements, a caliper brake is for braking the drum, and a safety catch is not the specific device for overwinding prevention in this context.
Controller of Mines • 2026 • Technical Paper-II
Main advantage of using main and tail rope haulage is:
A)
No derailment of tub occurs.
B)
Suitable for high output.
C)
Suitable for undulating roadways and one operator can drive both drums.
D)
Long train of tubs can be attached.
Main and tail rope haulage is especially useful on steep or undulating roadways because the two ropes provide controlled movement in both directions. Its key advantage is that one operator can control both drums from a single position. Option (a) is incorrect because derailment prevention is not the main advantage. Option (b) is too general; high output is more associated with rope haulage systems in general, not the specific main-and-tail arrangement. Option (d) is also not the defining advantage of main and tail rope haulage.
Controller of Mines • 2026 • Technical Paper-II
Which of the following is the oxidizing agent in an explosive?
A)
Charcoal
B)
Aluminum
C)
Ammonium nitrate
D)
Magnesium carbonate
In an explosive, the oxidizing agent supplies oxygen needed for rapid combustion of the fuel component. Ammonium nitrate is a common oxidizer used in explosives. Charcoal is a fuel, aluminum is also a fuel/additive, and magnesium carbonate is not used as the oxidizing agent in explosives.
Controller of Mines • 2026 • Technical Paper-II
The sequence of attachments between the winding rope and the cage is:
A)
bull chains, triangular plate, capel, detaching hook
B)
detaching hook, bull chains, triangular plate, capel
C)
triangular plate, bull chains, capel, detaching hook
D)
capel, detaching hook, bull chains, triangular plate
In a winding arrangement, the load path from the winding rope to the cage follows the usual order of fittings: the winding rope is first attached to the triangular plate, then to the bull chains, then to the capel, and finally to the detaching hook connected to the cage. Therefore, option (c) gives the correct sequence. The other options place these fittings in an incorrect order.
Controller of Mines • 2026 • Technical Paper-II
To prevent slope failure the blasting system selected should be:
A)
Pre-split
B)
Muffled
C)
Deck charging
D)
All of the above
To prevent slope failure, the preferred blasting method is **pre-split blasting**. It creates a smooth, controlled final rock face and reduces vibration and overbreak, thereby helping maintain slope stability.
- **Pre-split**: Correct, because it is specifically used to control the final slope and prevent damage beyond the intended blast line.
- **Muffled**: Used mainly to reduce noise and flying fragments, not specifically for slope stability.
- **Deck charging**: Used to control charge distribution and reduce explosive energy, but it is not the primary method for preventing slope failure.
- **All of the above**: Incorrect, since only pre-split is directly aimed at preventing slope failure.
Controller of Mines • 2026 • Technical Paper-II
The ground distance between the mine manager’s office and pit top is 300 m and it is represented by 3 cm in the mine plan. What is the representative factor?
Controller of Mines • 2026 • Technical Paper-II
Explain the working principle of GPS.
Controller of Mines • 2026 • Technical Paper-II
It is proposed to connect two straights of a road by a simple circular curve. If the maximum speed of the vehicle is 60 km/h and the centrifugal ratio for the road is ¼, calculate the minimum radius of the curve in metre.
Controller of Mines • 2026 • Technical Paper-II
At zero oxygen balance, the ratio of oxidizers to fuel ratio for ANFO is:
A)
92 : 8
B)
93 : 7
C)
94 : 6
D)
95 : 5
ANFO (ammonium nitrate fuel oil) at zero oxygen balance is typically mixed in the ratio of about 94% ammonium nitrate to 6% fuel oil by weight. Among the given options, the closest standard ratio is 93 : 7. This corresponds to the commonly cited zero oxygen balance composition for ANFO. The other options are either too low or too high in fuel content.
Controller of Mines • 2026 • Technical Paper-II
No drill shall be used for boring a shot hole unless it allows a clearance of at least “A” cm over the diameter of the explosive cartridge. “A” is given by:
A)
0.5
B)
1
C)
2
D)
0.3
Under blasting regulations, the drill used for boring a shot hole must provide a clearance of at least 1 cm over the diameter of the explosive cartridge. This ensures smooth insertion of the cartridge without forcing it, which could damage the explosive or create unsafe conditions. Therefore, the correct answer is 1 cm. The other options (0.5 cm, 2 cm, and 0.3 cm) do not match the prescribed minimum clearance.
Controller of Mines • 2026 • Technical Paper-II
A 1100 V, 3 power supply system of a mine draws a load of 185 kW. The ammeter reading shows 115 A. Calculate the power factor of the system.
Controller of Mines • 2026 • Technical Paper-II
The method of leveling adopted to determine the difference of level between two points at a considerable distance apart with great precision is:
A)
Hypsometry
B)
Profile levelling
C)
Reciprocal levelling
D)
Trigonometrical levelling
Reciprocal levelling is used to determine the difference in level between two points that are far apart, especially when direct leveling is affected by obstacles like a river, valley, or other obstruction. It eliminates errors due to collimation, curvature, and refraction, so it gives high precision. Profile levelling is used to obtain the longitudinal profile of the ground, trigonometrical levelling uses measured angles and distances, and hypsometry is not the standard method for precise differential leveling.
Controller of Mines • 2026 • Technical Paper-II
Explain the factors affecting the selection of a mine pump and define the terms capacity and head.
Controller of Mines • 2026 • Technical Paper-II
No shot shall be fired unless the length of fuse is at least “A” meter. A is given by:
A)
1.2 m
B)
1.8 m
C)
2.5 m
D)
4 m
Under the blasting regulations in Indian mining practice, a shot should not be fired unless the fuse length is at least 1.2 metres. This minimum length provides sufficient time for the blaster to move to a safe distance after lighting the fuse. The other options are not the prescribed minimum length.
Controller of Mines • 2026 • Technical Paper-II
What indication do we get when contour lines lie closer?
A)
It means that slope of land is gentle
B)
It means that slope of land is steep
C)
It means that the land is flat
D)
It does not give any indication
Contour lines represent points of equal elevation. When the lines are closer together, the elevation changes rapidly over a short horizontal distance, which indicates a steep slope. If the contour lines are farther apart, the slope is gentle. Therefore, option (b) is correct.
Controller of Mines • 2026 • Technical Paper-II
Light wave travel with a velocity of:
A)
3 × 1010 cm/s
B)
3 × 1011 cm/s
C)
3 × 1012 cm/s
D)
3 × 1013 cm/s
The speed of light in vacuum is approximately 3 × 10^8 m/s. Converting to cm/s: 3 × 10^8 × 100 = 3 × 10^10 cm/s. Therefore, option (a) is correct. The other options are too large by powers of 10.
Controller of Mines • 2026 • Technical Paper-II
Explain in brief the different types of Conveyor Transport used in Mines.
Controller of Mines • 2026 • Technical Paper-II
In ambient air of industrial area, the permissible concentration of suspended particulate matter (PM10) measured on 24 hours average in µg/m3 is:
A)
100
B)
200
C)
300
D)
400
As per the National Ambient Air Quality Standards (NAAQS) in India, the permissible 24-hour average concentration of PM10 in industrial/residential/rural and other areas is 100 µg/m3. Therefore, the correct answer is 100. The other options are higher than the prescribed standard.
Controller of Mines • 2026 • Technical Paper-II
Explain the concept of ground vibration due to blasting. Discuss the methods of its control and the DGMS permissible limits of Peak Particle Velocity (PPV) for different structures.
Controller of Mines • 2026 • Technical Paper-II
Briefly discuss the main ingredients of an explosive, namely: the Oxidizer, Fuel, and Sensitizer.
Controller of Mines • 2026 • Technical Paper-II
The maximum permissible angle of fleet should not exceed:
A)
1
B)
1.5
C)
2
D)
2.5
In conveyor transport, the maximum permissible angle of fleet is typically limited to 1.5° to ensure safe and stable movement of the conveyor system. A larger angle can cause misalignment and operational issues. Therefore, 1.5 is the correct answer, while 1, 2, and 2.5 do not match the standard permissible limit.
Controller of Mines • 2026 • Technical Paper-II
A coal heading 4m wide and 2.5 metre high has an advance of 1 metre per cycle. The amount of explosive used in blasting is 6 kg. Taking specific gravity of coal as 1.5, calculate the powder factor.
Controller of Mines • 2026 • Technical Paper-II
In case of opencast mine blasting, the danger zone comprises of area within the diameter of:
A)
400 m
B)
500 m
C)
600 m
D)
300 m
Under blasting regulations for opencast mines, the danger zone is taken as the area within a diameter of 500 metres. Hence, option (b) is correct. The other options (300 m, 400 m, and 600 m) do not match the standard danger-zone limit specified for opencast mine blasting.
Controller of Mines • 2026 • Technical Paper-II
The sound pressure level is measured as 5 × 10-4 N/m2. What is the noise level in dB?
Controller of Mines • 2026 • Technical Paper-II
Tractive effort of a locomotive is given by:
A)
W/µ
B)
µ. W
C)
W - µ
D)
W + µ
Correct option B: µ. W
