NEETS 13 CH 3

Question 1

What is the sign of operation for the X-OR gate?

Answer 1

⊕.

Question 2

What will be the output of an X-OR gate when both inputs are HIGH?

Answer 2

Low (0).

Question 3

A two-input X-OR gate will produce a HIGH output when the inputs are at what logic levels?

Answer 3

One or the other of the inputs must be HIGH, but not both at the same time.

Question 4

What type of gate is represented by the output Boolean expression T ⊕R ?

Answer 4

Exclusive NOR (X-NOR).

Question 5

What will be the output of an X-NOR gate when both inputs are LOW?

Answer 5

HIGH.

Question 6

What advantage does a half adder have over a quarter adder?

Answer 6

The half adder generates a carry.

Question 7

An X-OR gate may be used as what type of adder?

Answer 7

Quarter adder.

Question 8

What will be the output of a half adder when both inputs are 1s?

Answer 8

Sum equals 0 with a carry of 1.

Question 9

What type of adder is used to handle a carry from a previous circuit?

Answer 9

Full adder.

Question 10

How many full adders are required to add four-digit numbers?

Answer 10

Four.

Question 11

With the inputs shown below, what will be the output of S1, S2, and C2?

Answer 11

S1 = 1, S2 = 0 and C2 = 1.

Question 12

What is the output of C1?

Answer 12

C1 = 0

Question 13

What type of logic gates are added to a parallel adder to enable it to subtract?

Answer 13

X-OR gates.

Question 14

How many of these gates would be needed to add a four-digit number?

Answer 14

Four.

Question 15

In the add mode, what does the output of C2 indicate?

Answer 15

MSD of the sum.

Question 16

In the subtract mode, a 1 at C0 performs what portion of the R’s complement?

Answer 16

Add 1 portion.

Question 17

In the subtract mode, which portion of the problem is complemented?

Answer 17

Subtrahend.

Question 18

What are R-S FFs used for?

Answer 18

Storing information.

Question 19

How many R-S FFs are required to store the number 1001012?

Answer 19

Six.

Question 20

For an R-S FF to change output conditions, the inputs must be in what states?

Answer 20

1 and 0, or opposite states.

Question 21

How may R-S FFs be constructed?

Answer 21

By cross-coupling NAND or OR gates.

Question 22

How many inputs does a T FF have?

Answer 22

One.3-45

Question 23

What is the purpose of using T FFs?

Answer 23

To divide the input by 2

Question 24

What are the inputs to a D FF?

Answer 24

Clock and data.

Question 25

How long is data delayed by a D FF?

Answer 25

Up to one clock pulse.

Question 26

What condition must occur to have a change in the output of a D FF?

Answer 26

A positive-going clock pulse.

Question 27

What type of FF can be used as an R-S, a T, or a D FF?

Answer 27

J-K flip-flop.

Question 28

What will be the output of Q if J is HIGH, PS and CLR are HIGH, and the clock is going negative?

Answer 28

Set, or HIGH (1).

Question 29

Assume that K goes HIGH and J goes LOW; when will the FF reset?

Answer 29

When the clock pulse goes LOW.

Question 30

What logic levels must exist for the FF to be toggled by the clock?

Answer 30

Both J and K must be HIGH.

Question 31

What two inputs to a J-K FF will override the other inputs?

Answer 31

Clear (CLR) and preset (PS or PR).

Question 32

How is the J-K FF affected if PS and CLR are both LOW?

Answer 32

The flip-flop is jammed.

Question 33

What is a clock with regard to digital equipment?

Answer 33

A timing signal.

Question 34

What is the simplest type of clock circuit?

Answer 34

An astable or free-running multivibrator.

Question 35

What is needed to use a monostable or one-shot multivibrator for a clock circuit?

Answer 35

Triggers

Question 36

What type of clock is used when more than one operation is to be completed during one clock cycle?

Answer 36

A multiphase clock

Question 37

What is the modulus of a five-stage binary counter?

Answer 37

32

Question 38

An asynchronous counter is also called a ___________ counter

Answer 38

Ripple.

Question 39

J-K FFs used in counters are wired to perform what function?

Answer 39

Toggle.

Question 40

What type of counter has clock pulses applied to all FFs?

Answer 40

Synchronous.

Question 41

In figure 3-24, view A, what logic element enables FF3 to toggle with the clock?

Answer 41

The AND gate.

Question 42

What is the largest count that can be indicated by a four-stage counter?

Answer 42

11112, or 1510.

Question 43

How many stages are required for a decade counter?

Answer 43

Four

Question 44

In figure 3-25, which two FFs must be HIGH to reset the counter?

Answer 44

FFs 2 and 4.

Question 45

In figure 3-26, view A, which AND gate causes FF3 to set?

Answer 45

Two

Question 46

Which AND gate causes FF3 to reset?

Answer 46

Three.

Question 47

What causes the specified condition to shift position?

Answer 47

The input, or clock pulse.

Question 48

If the specified state is OFF, how many FFs may be off at one time?

Answer 48

One.

Question 49

How many FFs are required to count down from 1510?

Answer 49

Four.

Question 50

What signal causes FF2 to toggle?

Answer 50

Q output of FF 1 going LOW.

Question 51

How many stages are required to store a 16-bit word?

Answer 51

. 16.

Question 52

Simultaneous transfer of data may be accomplished with what type of register?

Answer 52

Parallel

Question 53

How are erroneous transfers of data prevented?

Answer 53

By clearing the register.

Question 54

Serial-to-parallel and parallel-to-serial conversions are accomplished by what type of circuit?

Answer 54

Shift register.

Question 55

What type of data transfer requires the most time?

Answer 55

Serial

Question 56

What is the main disadvantage of parallel transfer?

Answer 56

Requires more circuitry.

Question 57

How many FFs would be required for an 8-bit shift register?

Answer 57

Eight.

Question 58

How many clock pulses are required to output a 4-bit number in serial form?

Answer 58

Four

Question 59

Two shifts to the left are equal to increasing the magnitude of a number by how much?

Answer 59

22, or four times.

Question 60

To increase the magnitude of a number by 23, you must shift the number how many times and in what direction?

Answer 60

Three to the left.

Question 61

What are RTL, DTL, and TTL examples of?

Answer 61

Logic families

Question 62

What type of logic family uses diodes in the input?

Answer 62

DTL (diode transistor logic).

Question 63

What is the most common type of integrated circuit packaging found in military equipment?

Answer 63

DIPs (dual inline packages).

Question 64

Circuits that can be interconnected without additional circuitry are known as ____________ circuits.

Answer 64

Compatible.