Interfacing to the Analog World MCQs

Question 1

Why is a binary-weighted DAC usually limited to 4-bit binary conversion?

Accepted Answer

too many different values of resistors

Answer

too many pins on the IC

Answer

too many op amps needed

Answer

too many different values of capacitors

Question 2

What is the resolution of a D/A converter?

Accepted Answer

It is the reciprocal of the number of discrete steps in the D/A output.

Answer

It is the comparison between the actual output of the converter and its expected output.

Answer

It is the deviation between the ideal straight-line output and the actual output of the converter.

Answer

It is the converter's ability to resolve between forward and reverse steps when sequenced over its entire range of inputs.

Question 3

An actuator is usually a device that:

Accepted Answer

controls a physical variable.

Answer

converts analog data to meaningful digital data.

Answer

stores digital data and then processes that data according to a set of specified instructions.

Answer

converts a physical variable to an electrical variable.

Question 4

There are many applications in which analog data must be digitized and transferred into a computer's memory. The process by which the computer acquires these digitized analog data is referred to as ________.

Accepted Answer

data acquisition

Answer

sampling

Answer

multiplexing

Answer

prescaling

Question 5

When analog inputs from several sources are to be converted, a(n) ________ technique can be used.

Accepted Answer

multiplexing

Answer

demultiplexing

Answer

R/2R

Answer

comparator

Question 6

The stability of the ADC process can be improved by using a(n) ________ to hold the analog voltage constant while the A/D conversion is taking place.

Accepted Answer

sample-and-hold circuit

Answer

op-amp comparator

Answer

NPN amp

Answer

current loop

Question 7

The characteristic that a change of one binary step on the input of a DAC should cause exactly one step change on the output is called ________.

Accepted Answer

monotonicity

Answer

resolution

Answer

linearity

Answer

accuracy

Question 8

On a binary-weighted D/A converter the least significant binary input ________.

Accepted Answer

connects to the largest resistor

Answer

connects to the smallest resistor

Answer

supplies the least voltage

Answer

connects to a 1 k resistor

Question 9

________ ADCs use no clock signal, because there is no timing or sequencing required.

Accepted Answer

Flash

Answer

Actuator

Answer

Dual

Answer

Bipolar