Final answer:
The file extension to be downloaded is .hex
Step-by-step explanation:
The file extension name to be downloaded to the PIC16F MCU while using PICKIT2 software is .hex.
When using PICKIT2 software, the programming tool generates a hex file that contains the machine code instructions for the microcontroller. This hex file is then downloaded to the PIC16F MCU using the software.
By using the .hex file, the PICKIT2 software can program the PIC16F MCU with the correct instructions, allowing the microcontroller to perform its desired functions.