Which of the following notational systems represents physical electrical impulses going into electronic and computing devices?

Decimal is a base-10 numeral system used by humans for counting, not directly by electronic devices for fundamental operations.

Binary, a base-2 numeral system, uses only two symbols, typically 0 and 1, to represent data. These two states directly correspond to the physical electrical impulses (e.g., presence or absence of voltage, or high/low voltage) that electronic and computing devices process.

Hexadecimal is a base-16 numeral system often used by humans to represent large binary values more compactly, but it is not the direct representation of electrical impulses.

ASCII is a character encoding standard that assigns numerical values to characters, which are then represented in binary, but ASCII itself is not the notational system for electrical impulses.