What is the primary objective of man-riding systems in mines?
C
Safe and efficient transport of personnel
Analysis & Theory
Man-riding systems are designed to transport miners safely and quickly within mines.
Which of the following is a common man-riding arrangement in underground mines?
Analysis & Theory
Belt man-riding systems are used for transporting miners on conveyor belts in long roadways.
Man-riding is generally introduced in roadways longer than:
Analysis & Theory
Man-riding systems are installed in haulage roadways over 800 m for time and energy saving.
Which man-riding system uses a train of tubs pulled by locomotives?
Analysis & Theory
Rail man-riding uses locomotives to transport miners in specially designed man-riding cars.
A major advantage of belt man-riding systems is:
A
They move faster than rail cars
B
Less costly and already available belt infrastructure can be used
C
Higher speed makes them unsafe
Analysis & Theory
Existing belt conveyors can be adapted for man riding, reducing additional cost.
Which safety provision is **mandatory** in a man-riding belt system?
C
Emergency stop cords along both sides
Analysis & Theory
Emergency stop ropes or cords are required on both sides to stop the belt in an emergency.
A major limitation of man-riding belts is:
B
Over-speeding capability
C
Not suitable for steep gradients
Analysis & Theory
Belt man-riding is restricted to gradients not exceeding 18°.
Chair lifts are mostly used in:
B
Inclined and undulating roadways
Analysis & Theory
Chair lifts are useful in inclined roadways where belts or rail are not feasible.
Which of the following is NOT a type of pump used in mines?
Analysis & Theory
Jet pumps are rarely used in mining; centrifugal and reciprocating types are more common.
Centrifugal pumps are mainly used in mines for:
A
High-pressure low-flow jobs
B
Low-pressure high-flow pumping
Analysis & Theory
Centrifugal pumps are ideal for high-volume dewatering jobs.
The main advantage of centrifugal pumps is:
A
Simple design and continuous flow
C
Best for viscous liquids
Analysis & Theory
Centrifugal pumps are reliable, simple, and good for large flow rates.
Reciprocating pumps are preferred when:
A
Large flow rate is required
B
Water is to be lifted to great height
D
No power supply available
Analysis & Theory
Reciprocating pumps are positive displacement pumps and ideal for high-head applications.
A drawback of reciprocating pumps is:
D
Pulsating flow and complex design
Analysis & Theory
Reciprocating pumps produce pulsating flow and require more maintenance.
Which of the following is used to remove water from the sump at pit bottom?
Analysis & Theory
Submersible pumps are often placed in the sump for dewatering.
Which pump is ideal for handling water with a high percentage of solids?
Analysis & Theory
Slurry pumps are designed to handle abrasive solids and slurry mixtures.
In multi-stage centrifugal pumps, multiple impellers are used to:
B
Increase suction capacity
Analysis & Theory
Each stage adds to the total head developed by the pump.
A limitation of submersible pumps is that they:
B
Cannot operate underwater
C
Need regular lifting for inspection
Analysis & Theory
Submersible pumps need to be retrieved periodically for maintenance and inspection.
Which of the following is a major hazard with pump installations in mines?
A
Dry running and motor burnout
Analysis & Theory
Running pumps without water (dry running) can cause overheating and damage to the motor.
Pump capacity is expressed in:
B
Litres per second or m³/hour
Analysis & Theory
Pump capacity is measured in volume of fluid moved per unit time.
Which man-riding system is considered the most flexible?
Analysis & Theory
Chair lifts can operate in varying gradients and curvatures with minimal modifications.
What does NPSH stand for in pump operations?
A
Net Positive Suction Head
B
Normal Pumping Safety Head
C
Nominal Pressure at Suction Height
Analysis & Theory
NPSH is important to avoid cavitation in pumps.
Which pump component helps convert velocity energy into pressure energy?
C
Diffuser or volute casing
Analysis & Theory
The casing (volute or diffuser) helps convert kinetic energy to pressure energy.
Which pump is preferred for drainage in mines located in remote areas with irregular power supply?
B
Submersible electric pump
Analysis & Theory
Diesel pumps can run independently and are useful during emergencies or power failures.
Which pump has the **simplest construction** and is widely used in mines?
Analysis & Theory
Centrifugal pumps are simple, cost-effective, and commonly used.
In shaft sinking operations, pumps are used primarily for:
Analysis & Theory
During shaft sinking, dewatering is essential to keep the site operable and safe.
Which is a **key requirement** for a man-riding car used on rail?
C
Friction brakes and locking doors
Analysis & Theory
Man-riding cars must have safety features like friction brakes and enclosed compartments.
Axial flow pumps are used in mines when:
A
Low flow and high head are required
B
High flow and low head are required
D
Only gas is to be moved
Analysis & Theory
Axial flow pumps deliver large quantities of water at low heads efficiently.
Which of the following is a **merit** of man-riding systems?
C
Saves travel time and improves safety
Analysis & Theory
Man-riding saves time and minimizes physical strain on workers.
Which organization regulates safety guidelines for man-riding in Indian mines?
Analysis & Theory
DGMS (Directorate General of Mines Safety) issues safety protocols for man-riding.