Maintenance Electrician Interview Questions and Answers for Freshers

Copper loss or I2R loss depends on current while iron or core loss depends on voltage in transformers.

• Copper loss is the power lost due to the resistance of the copper wire in the transformer winding.

• Iron or core loss is the power lost due to the magnetic properties of the transformer core.

• Higher current leads to higher copper loss while higher voltage leads to higher iron or core loss.

• Efficiency of the transformer can be improved by reducing both copper and iron losses.

A DOL starter is a direct-on-line starter used in electrical systems to start and stop motors.

• DOL stands for Direct-On-Line.

• It is the simplest and most common type of motor starter.

• The DOL starter directly connects the motor to the power supply, providing full voltage at start.

• It consists of a contactor, overload relay, and start and stop buttons.

• When the start button is pressed, the contactor closes and the motor starts.

• The overload relay protects the motor from excessive cu...read more

True, losses in transformers are independent of power factor.

• Transformer losses occur due to core losses and copper losses

• Core losses are constant and independent of load power factor

• Copper losses vary with load but are also independent of power factor

• Power factor affects only the apparent power and not the losses

MCCB and MCB are circuit breakers that protect electrical circuits from overloads and short circuits, ensuring safety and reliability.

• MCB (Miniature Circuit Breaker) protects against overloads and short circuits in low voltage applications.

• MCCB (Molded Case Circuit Breaker) is used for higher current ratings and provides protection against overloads and short circuits.

• MCBs are typically rated up to 100A, suitable for residential and light commercial use.

• MCCBs can handle curre...read more

The company was founded in 1995, focusing on innovative electrical solutions and maintenance services for various industries.

• Founded in 1995, the company started with a small team of skilled electricians.

• Initially focused on residential electrical services, it expanded to commercial and industrial sectors.

• The company has grown significantly, now serving clients across multiple states.

• In 2005, the company introduced advanced maintenance programs to enhance service efficiency.

The unit of specific conductivity is Siemens per meter (S/m).

• Specific conductivity is a measure of the ability of a material to conduct electricity.

• It is the reciprocal of resistivity.

• Examples of materials with high specific conductivity include metals like copper and aluminum.

• Water with dissolved ions also has a specific conductivity.

• Specific conductivity is important in industries like electronics and water treatment.

The unit of specific resistance is ohm-meter (Ω·m).

• Specific resistance is a measure of how strongly a material opposes the flow of electric current.

• It is also known as resistivity.

• The unit ohm-meter represents the resistance between opposite faces of a 1-meter cube of the material.

• Specific resistance depends on the material's composition, temperature, and other factors.

Transformer safety ensures protection against electrical hazards and equipment damage during operation and maintenance.

• Prevents electrical shock: Transformers are designed with insulation and grounding to protect users.

• Overcurrent protection: Fuses or circuit breakers are used to prevent damage from excessive current.

• Temperature monitoring: Devices like thermal relays help prevent overheating, ensuring safe operation.

• Regular maintenance: Routine checks and servicing help iden...read more