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

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

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 iss...read more