# Advanced Solid-State Logic: Flip-Flops, Shift Registers, Counters, and Timers: Quiz

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## Questions

1. Explain how NAND logic gates can be used to make an RS latch.

2. Provide an example of an industrial application that uses an RS latch and explain the operation of the application.

3. Explain the difference between a latch and a flip-flop.

4. Provide an example of an industrial application that uses a FIFO.

5. Explain the operation of a bit shift register.

6. Provide an example of an industrial application that uses a bit shift register.

7. Explain the difference between a bit shift register and a word shift register.

8. Provide an example of an industrial application that uses a word shift register.

9. Explain the operation of a ring counter.

10. Explain the operation of a Johnson counter.

## TRUE or FALSE

1. ______ An RS latch will have an output at Q any time the S input is HI.

2. _______ An edge-triggered flip-flop will only change state when a pulse has transitioned the clock input.

3. _______ A shift register stores the value at the data input and shifts it to the right or left one bit each time a clock pulse is received.

4. ______ An edge-triggered flip-flop changes its output only when a clock pulse occurs at the clock input.

5. _______ The gray code is used in encoders because it has more bits than the binary code, which means it can count larger numbers.

## Multiple Choice

1. The RS latch will provide an output at its Q output when____.

a. S is HI and R is HI

b. S is HI and R is LO

c. S is LO and R is HI.

2. The edge-triggered JK flip-flop shown in Fig. 3 will have its Q output HI when___.

a. J is HI, K is LO, and the clock pulse transitions from the off to the on state.

b. J is HI, K is HI, and the clock pulse transitions from the on to the off state.

c. J is LO, K is HI, and the clock pulse transitions from the off to the on state.

3. The ring counter uses ______

a. four flip-flops to count values 0—9.

b. ten flip-flops to count values 0—9.

c. four flip-flops to count values 0—7.

d. ten flip-flops to count values 0—7

4. The motor starter coil for compressor 1 connected to the Q output of the edge-triggered JK flip-flop in Fig. 4 ______

a. energizes every other time the pressure switch PS1 closes.

b. energizes every time the pressure switch PS1 closes.

c. energizes every time safety switch PS2 or PS3 closes.

5. A one-shot timer _______

a. provides a series of short output pulses every 0.1 second as long as it receives a HI enable signal.

b. provides a single output pulse of short duration regardless of the duration of the input pulse.

c. provides a time delay-on function between 1-10 seconds.

## Problems

1. Sketch the diagram of an RS latch and identify its input and output terminals.

2. Sketch the truth table for an RS latch.

3. Draw a 555 timer used as a monostable vibrator and identify its inputs and outputs.

4. Sketch the diagram of an edge-triggered RS flip-flop and identify its input and output terminals.

5. Draw the symbol for on-delay timer contacts (delay on) and off-delay timer contacts (delay off) and explain how each operates.  Solution to Job Assignment Home