A diode installed across a coil with the cathode toward the battery positive is called ________.

A diode installed across a coil with the cathode toward the battery positive is correctly identified as a clamping diode, also known as a flyback diode. Its primary function is to protect electronic circuits from voltage spikes caused by the inductor's reaction when the current flowing through it is suddenly interrupted. When the current through the coil is turned off, the collapsing magnetic field generates a high-voltage spike in the opposite direction, which could potentially damage other components in the circuit.

The clamping diode provides a path for the current generated by this voltage spike, allowing it to circulate through the coil instead of affecting the rest of the circuit adversely. By doing so, the diode clamps the voltage to a level that protects sensitive components.

In terms of other options, a forward-biased diode refers to a diode operating in its conducting state, which is not specifically related to the protective function discussed. An SCR, or silicon-controlled rectifier, is a semiconductor device used for controlling power, and while it can manage inductive loads, it serves a different purpose than the diode in this context. A transistor, while it can also be part of a coil circuit, functions differently and is used for switching and amplification rather than protection against voltage spikes. Hence, the