A backfire is characterized by a loud ____________________.

A backfire is characterized by a loud pop sound. This phenomenon occurs when there is an unexpected ignition of the gas in the torch or the combustion area. This loud noise is a result of the rapid expansion of gases that have ignited, creating a sharp sound.

The term "pop" effectively describes the suddenness and abruptness of the noise produced during a backfire event. Understanding the nature of the sound aids in recognizing the occurrence and ensuring proper safety and operational protocols are followed when using gas-fueled equipment. Identification of a backfire by its sound allows for timely adjustments to the equipment, preventing further issues in the brazing process.