Decade Counter

Correct Answer

C — a BCD counter

Concept and Reasoning

A counter that cycles through binary representations 0000 to 1001 has ten states corresponding to decimal digits 0 through 9. It is therefore a BCD/decade counter, which is option C.

Calculation / Key Relation

BCD decade count: 0000 through 1001 → modulus 10

Exam Takeaway

BCD counter stops normal sequence at decimal 9, not binary 15.

Common Mistake

Do not call a four-bit decade counter an ordinary mod-16 binary counter.