Deep Dive: E7A03
The correct answer is B: A flip-flop. Which of the following can divide the frequency of a pulse train by 2 is a flip-flop. Flip-flops divide frequency by 2. For amateur radio operators, this is important for digital circuits. Understanding this helps when dividing frequencies.
Why Other Answers Are Wrong
Option A (XOR gate): Incorrect. XOR gate doesn't divide frequency - flip-flops do. XOR gate isn't the answer. Option C (OR gate): Incorrect. OR gate doesn't divide frequency - flip-flops do. OR gate isn't the answer. Option D (Multiplexer): Incorrect. Multiplexer doesn't divide frequency - flip-flops do. Multiplexer isn't the answer.
Exam Tip
Divide frequency by 2 = flip-flop. Think 'F'lip-'F'lop = 'F'requency 'F'actor of 2 (divides by 2). Flip-flops divide frequency by 2. Not XOR gate, not OR gate, not multiplexer - just flip-flop.
Memory Aid
Divide frequency by 2 = flip-flop. Think 'F'lip-'F'lop = 'D'ivides by '2'. Flip-flops divide frequency by 2. Important for digital circuits.
Real-World Example
Dividing the frequency of a pulse train by 2: A flip-flop can do this. Each flip-flop stage divides the frequency in half. This is what can divide by 2 - flip-flop.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E7A
Reference: 2024-2028 Question Pool · E7 - Practical Circuits
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E7A topic.