Lap winding is preferred for which type of machines:
- High current and high voltage
- Low current and low voltage
- Low current and high voltage
- High current and low voltage
Correct answer: 4. High current and low voltage
Explanation: Lap winding is preferred for machines where a high current is required at low voltage, such as in DC machines. In particular, lap winding is commonly used in DC generators and DC motors.
Lap winding is characterized by the fact that the armature coils are connected in parallel. This configuration allows for the division of the total armature current among multiple parallel paths, reducing the current flowing through each individual coil. As a result, the voltage drop across each coil is minimized, which is advantageous for machines that operate at low voltages and high currents.
In lap winding, the number of parallel paths is equal to the number of poles in the machine. This design helps in achieving a more effective distribution of current and reducing the risk of excessive voltage drop. The winding is called “lap” because the winding coils overlap each other as they traverse the core of the machine.
In contrast, wave winding is another winding configuration used in DC machines, where the coils are connected end-to-end, forming a wave-like pattern. Wave winding is more suitable for machines where a higher voltage is required at the expense of handling lower currents.
In summary, lap winding is preferred for machines that operate at low voltage and high current, such as DC generators and motors.