10+ Coal India Interview Questions and Answers for Freshers

The lack of high-rise buildings in India can be attributed to various factors such as land availability, building regulations, cultural preferences, and infrastructure limitations.

• Limited availability of land in urban areas restricts the construction of high-rise buildings.

• Building regulations and zoning laws often impose height restrictions and setback requirements.

• Cultural preferences in India often favor low-rise buildings that promote a sense of community and connection w...read more

A haul road is a road used for transporting materials, typically in a mining or construction site.

• Haul roads are designed to handle heavy loads and are often unpaved.

• They are used to transport materials such as ore, rock, and dirt.

• Haul roads must be maintained regularly to ensure safety and efficiency.

• Proper drainage is important to prevent erosion and maintain road stability.

• Examples of haul road equipment include haul trucks, graders, and water trucks.

A flame safety lamp is a type of lamp used in mining to detect methane gas and prevent explosions.

• It works by creating a flame inside a mesh screen that will go out if methane is present.

• The lamp was invented by Sir Humphry Davy in 1815.

• It was widely used in coal mines in the 19th and early 20th centuries.

• Today, electronic gas detectors have largely replaced flame safety lamps in mining.

Portable machines can be easily carried around, while transportable machines require disassembly and reassembly for transportation.

• Portable machines are designed to be easily moved from one location to another without much effort.

• Transportable machines require disassembly and reassembly for transportation.

• Portable machines are usually smaller and lighter than transportable machines.

• Examples of portable machines include laptops, tablets, and handheld gaming devices.

• Examples of...read more

Safety devices of Direct Haulage include emergency stop buttons, warning signals, and safety barriers.

• Emergency stop buttons are installed at regular intervals along the haulage route.

• Warning signals such as flashing lights and alarms are used to alert workers of approaching haulage equipment.

• Safety barriers are used to prevent workers from entering hazardous areas.

• Proximity detection systems are used to detect the presence of workers and automatically stop the haulage equipm...read more

The calorific value of coal varies depending on the type of coal, but typically ranges from 24 to 30 megajoules per kilogram.

• Calorific value is the amount of heat released when a substance is burned.

• It is measured in units of energy per unit of mass, such as joules per gram or megajoules per kilogram.

• The calorific value of coal can vary depending on factors such as moisture content, ash content, and sulfur content.

• For example, anthracite coal has a higher calorific value than...read more

Sharp corners are avoided in casting to prevent stress concentration and improve the overall strength and quality of the casting.

• Sharp corners can lead to stress concentration, which can cause cracks or failure in the casting.

• Rounded corners distribute stress more evenly, reducing the likelihood of defects.

• Sharp corners can also create difficulties during the casting process, such as mold filling and solidification issues.

• Examples of avoiding sharp corners include filleting o...read more

An induction motor is a type of AC motor that works on the principle of electromagnetic induction to convert electrical energy into mechanical energy.

• Induction motors are commonly used in various industrial applications due to their simplicity, reliability, and low cost.

• They consist of a stator (stationary part) and a rotor (rotating part) where the rotor is not connected to an external power source.

• When an alternating current is applied to the stator windings, a rotating mag...read more

Treatment for TB involves a combination of antibiotics taken for several months.

• Treatment for TB typically involves a combination of antibiotics such as isoniazid, rifampin, ethambutol, and pyrazinamide.

• The duration of treatment can vary but is usually around 6 to 9 months.

• Directly Observed Therapy (DOT) is often recommended to ensure adherence to the treatment regimen.

• Patients with drug-resistant TB may require different medications and longer treatment duration.

• Treatment sh...read more

Substation use equipment refers to the various devices and tools used in a substation for power distribution and maintenance.

• Substation transformers

• Circuit breakers

• Disconnect switches

• Voltage regulators

• Capacitor banks

• Protective relays

A generator is a device that converts mechanical energy into electrical energy. It functions by rotating a coil of wire within a magnetic field to produce electricity.

• Generates electricity by converting mechanical energy into electrical energy

• Consists of a coil of wire rotating within a magnetic field

• Used in power plants, backup generators, and portable generators

Transformers function to change voltage levels in electrical systems.

• Transformers increase or decrease voltage levels in electrical systems

• Step-up transformers increase voltage for long-distance transmission

• Step-down transformers decrease voltage for distribution to homes and businesses

• Transformers help maintain power quality and efficiency in electrical grids