Topic: Digital Logic
A MOD-16 ripple counter using J-K flip-flop has a current state 1001. How many clock pulses are required to get the state 0000?
- A. 8
- B. 6
- C. 7
- D. 5
Answer: C. 7
Explanation: A MOD-16 counter counts sequentially from 0000 (0) to 1111 (15) before overflowing back to 0000.
The current state is $1001_2 = 9_{10}$.
To reach $0000_2 = 16_{10}$ (overflow state), the counter needs to advance by $16 - 9 = 7$ states.
Therefore, 7 clock pulses are required.