Brain Pick

Interview Q&A/ Technical Round: Short Q&A Section: Q1. What is Electrical Resistance? Resistance is the property of a material that opposes the flow of electric current. It depends on the material, length, cross-sectional area, and temperature of the conductor. Its unit is ohm (Ω). Q2. State Ohm’s Law. Ohm’s Law states that the current flowing through a conductor is directly proportional to the applied voltage, provided temperature remains constant. Mathematically, V = IR. Q3. What is Electric Current? Electric current is the rate of flow of electric charge in a conductor. It is measured in amperes (A) and is denoted by I. Q4. Define Electrical Power. Electrical power is the rate at which electrical energy is consumed or converted into another form. It is measured in watts (W) and given by P = VI. Q5. What is Electrical Energy? Electrical energy is the total work done by an electrical source over time. It is measured in  watt-hour (Wh) or kilowatt-hour (kWh). Q6. What ...

Aspect Induction Motor Synchronous Motor Operating Principle Operates on electromagnetic induction. Maintains synchronism with the rotating magnetic field. Speed Control Controlled by changing the frequency or using VFDs. Fixed speed based on the power supply frequency. Starting Mechanism Self-starting; does not require external devices. Typically requires external means for synchronization. Efficiency Generally slightly less efficient, especially at partial loads. Typically more efficient, especially for constant loads. Applications Pumps, fans, compressors, conveyor systems, household appliances. Power factor correction, synchronous conden...

Aspect Synchronous Motor Synchronous Generator Function Converts electrical energy into mechanical energy. Converts mechanical energy into electrical energy. Operation Requires an external mechanical force to start rotating. Requires an initial source of electrical energy to induce rotation. Speed Operates at synchronous speed. Generates electrical power at synchronous speed. Construction Often has additional mechanisms (e.g., squirrel cage rotor). Typically has a rotor with field windings. Torque Produces torque to overcome mechanical resistance. Requires mechanical input to produce torque for electricity generation. ...

  Characteristic Water Tube Boiler Fire Tube Boiler Tube Arrangement Water-filled tubes in the boiler Fire tubes contain hot gases Water Circulation Circulates water within tubes Water surrounds the fire tubes Heating Surface Area Larger heating surface area Smaller heating surface area Efficiency Higher thermal efficiency Lower thermal efficiency Response to Load Changes Faster response to load changes Slower response to load changes Pressure Range Suitable for high-pressure applications Typically lower pressure applications Drum Size Smaller drum size Larger drum size Safety Safer, as water surrounds the tubes Lower safety due to hot gases inside Maintenance Typically requires more maintenance Requires less maintenance Suitable for Plants Commonly used in ...

Characteristic Pelton Turbine (Impulse) Francis Turbine (Reaction) Kaplan Turbine (Reaction) Type of Flow High head, low flow rate Medium head and medium flow rate Low head, high flow rate Runner Design Cups or buckets Blades Adjustable blades Efficiency High efficiency at high heads High efficiency over a wide range High efficiency at low heads Applications Typically used in mountainous regions and for high-head hydroelectric power generation. Widely used for a variety of head and flow conditions in hydroelectric power plants. Suitable for low-head applications, such as in rivers and low-head dams. Blade Angle Control Fixed buckets, no adjustment Fixed blades, adjustable guide vanes Adjustable blades and wicket gates Turbine Size Range Typically smaller for portable or micro-hydro applications. Varied sizes, s...

Coal Fired/Steam/Thermal Power Station: Component Function Boiler Generates steam by burning coal, which drives the turbine. Economizer Heats the incoming feedwater using hot flue gases. Superheater Increases the temperature of steam after it leaves the boiler. Ash Handling System Collects and transports ash and other solid residues from the combustion process. Coal Handling System Stores and transports coal to the boiler for combustion. Air Preheater Heats the incoming combustion air using hot flue gases. Chimney Exhausts flue gases and emissions from the power plant. ID Fan Induced Draft Fan: Helps create a vacuum in the flue gas system, aiding in the removal of exhaust gases. FD Fan Forced Draft Fan: Supplies air to the combustion process in the boiler. Steam Turbine Converts high-pressure steam energy into ...