Polaris Senior Design Engineer Interview Questions and Answers

Dyn11 is a vector group notation used in transformers to indicate the phase displacement between primary and secondary windings.

• Dyn11 is a three-phase transformer with the primary winding connected in delta and the secondary winding connected in star with neutral grounded.

• The phase displacement between primary and secondary windings is 330 degrees.

• Dyn11 is commonly used in Europe and Asia for distribution transformers.

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Diesel has higher energy density than petrol, resulting in better fuel efficiency.

• Diesel has a higher energy density than petrol, meaning it can provide more energy per unit volume.

• Petrol is more volatile and burns faster than diesel.

• The capacity of diesel and petrol tanks in vehicles can vary depending on the size of the vehicle and its fuel efficiency.

• For example, a typical car may have a petrol tank capacity of arou...read more

Petrol engines use spark ignition, while diesel engines use compression ignition.

• Petrol engines use a spark plug to ignite the fuel-air mixture, while diesel engines rely on compression to ignite the fuel.

• Petrol engines are lighter and more responsive, while diesel engines are more fuel-efficient and have higher torque.

• Petrol engines are more common in cars and motorcycles, while diesel engines are often used in trucks

LNTD stands for Logarithmic Mean Temperature Difference.

• LNTD is a term used in heat transfer calculations to determine the overall temperature difference between two fluids in a heat exchanger.

• It is calculated using the formula LNTD = (ΔT1 - ΔT2) / ln(ΔT1 / ΔT2), where ΔT1 and ΔT2 are the temperature differences at the two ends of the heat exchanger.

• LNTD is important in designing efficient heat exchangers to maximize h...read more