Question

The selector inputs to an arithmetic/logic unit (ALU) determine the ____________

(a) Selection of the IC

(b) Arithmetic or logic function

(c) Data word selection

(d) Clock frequency to be used

The question was posed to me during an internship interview.

This interesting question is from 4-Bit Parallel Adder/Subtractor topic in portion Arithmetic Circuits of Digital Circuits

Answer 1

Right answer is (b) Arithmetic or logic function

For explanation I would say: An ALU performs basic arithmetic and logic operations and stores it in the accumulator. Examples of arithmetic operations are addition, subtraction, multiplication, and division. Examples of logic operations are comparisons of values such as NOT, AND and OR and any logical operations.