Final answer:
The tripping current of a melting alloy device is not adjustable because it is determined by the material properties of the alloy itself.
Step-by-step explanation:
The tripping current of a melting alloy device is not adjustable because it is determined by the material properties of the alloy itself.
When the current passing through the device exceeds its tripping current, the alloy melts and breaks the circuit, providing protection against excessive current.
For example, a common type of melting alloy device is a fuse, which is used to protect electrical circuits from overloads or short circuits.