Coal India Interview Questions, Process, and Tips

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 pre...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 ...read more

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...read more

To find the steel weight, you need to know the dimensions and density of the steel.

• Determine the dimensions of the steel (length, width, and height)

• Find the density of the specific type of steel being used

• Multiply the volume of the steel by its density to calculate the weight

• Weight (in kg) = Volume (in m^3) x Density (in kg/m^3)

There are 100 centimetres in one metre.

• One metre is equal to 100 centimetres.

• To convert metres to centimetres, multiply by 100.

• To convert centimetres to metres, divide by 100.

A transformer is an electrical device that transfers electrical energy from one circuit to another through electromagnetic induction.

• Transformers are used to increase or decrease the voltage of an alternating current (AC) power supply.

• They consist of two coils of wire, known as the primary and secondary coils, which are wrapped around a magnetic core.

• When an AC voltage is applied to the primary coil, it creates a magne...read more

The type of breaker used depends on the electrical load and the circuit requirements.

• The most common types of breakers are standard, AFCI, GFCI, and dual-function.

• Standard breakers are used for general-purpose circuits.

• AFCI breakers are used for circuits that power bedrooms and living rooms.

• GFCI breakers are used for circuits that power bathrooms, kitchens, and outdoor areas.

• Dual-function breakers combine AFCI and GFCI...read more

Conductors are materials that allow electricity to flow through them. There are different types of conductors used in electrical systems.

• Copper is the most commonly used conductor in electrical wiring

• Aluminum is also used as a conductor, especially in high voltage power transmission

• Silver is the best conductor, but it is too expensive for most applications

• Gold is also a good conductor, but it is even more expensive tha...read more

MCB is a miniature circuit breaker while MCCB is a molded case circuit breaker.

• MCB is used for low current applications while MCCB is used for high current applications.

• MCB is rated up to 100 amps while MCCB can be rated up to 2500 amps.

• MCCB has adjustable trip settings while MCB does not.

• MCCB is more expensive than MCB.

• Examples of MCB brands include Legrand and Schneider while examples of MCCB brands include Siemens a

The camshaft and crankshaft have different speeds in an engine.

• The camshaft controls the opening and closing of the engine's valves, while the crankshaft converts the reciprocating motion of the pistons into rotational motion.

• The camshaft rotates at half the speed of the crankshaft in a four-stroke engine.

• For example, if the crankshaft rotates at 6000 revolutions per minute (RPM), the camshaft will rotate at 3000 RPM.

• T...read more

CNC stands for Computer Numerical Control. It is a manufacturing process that uses pre-programmed computer software to control machine tools.

• CNC is a manufacturing process that automates the operation of machine tools.

• It uses computer software to control the movement and operation of the machines.

• CNC machines are widely used in industries such as automotive, aerospace, and electronics.

• G codes are a programming language...read more

Different types of chips in metal cutting include continuous chips, discontinuous chips, and built-up edge chips.

• Continuous chips are formed when the cutting tool continuously removes material from the workpiece.

• Discontinuous chips are formed when the cutting tool intermittently removes material, resulting in segmented chips.

• Built-up edge chips occur when the material being cut adheres to the cutting tool, forming a bu...read more

Discontinuous chips are formed in certain materials during machining processes.

• Discontinuous chips are formed in brittle materials like cast iron, ceramics, and glass.

• These materials have low ductility and tend to fracture during machining.

• The discontinuous chips have a segmented or broken appearance.

• They are characterized by irregular shapes and rough surfaces.

• Examples of materials that form discontinuous chips includ...read more