1990
1. Which of the following resistance networks can be used as 3
bit R-2R ladder DAC? Assume Vo corresponds to LSB.
a.
Both (i) and (ii)
b.
Both (i) and (iii)
c.
Only (iii)
d. Only (ii)
d. Only (ii)
Answer: C
Solution : https://www.youtube.com/watch?v=CQEUnS3slF4
Solution : https://www.youtube.com/watch?v=CQEUnS3slF4
1992
1. Dual slope integration type analog to digital converter
provide
a.
Higher speeds compared to all other
types of A/D converters
b.
Very good accuracy without putting
extreme requirements on
component
stability
c.
Good rejection of power supply hum
d.
Better resolution compared to all
other types of A/D converters for the same number of bits.
Answer: B & C
Solution : https://www.youtube.com/watch?v=aN33UvCFYhs
1994
1. Data can be changed from spatial code to temporal code and
vice-versa by using
a.
ADCs and DACs
b.
Shift registers
c.
Synchronous counters
d.
Timers
Answer: Shift registers
2. Match the following ADC’s with their Maximum conversion time
for 8 bit digital output.
Answer: a-2, b-4,c-1
Solution : https://www.youtube.com/watch?v=w5r0kH5Zqy4
1995
1. For an ADC, match the following
Answer: a-4, b-3, c-2
1996
1. A 12 bit ADC is operating with a 1 µsec clock period and the total conversion time is seen to be
14 µsec.
the ADC must be of the
a.
Flash type
b.
Counting type
c.
Integrating type
d.
Successive Approximation type
Answer: D
2. A 10 bit ADC with full scale output voltage of 10.24 volts
is designed to have a ±LSB/2 accuracy. If the ADC is calibrated at
25oC and the operating temperature ranges from 0oC to 50oC,
then the maximum net temperature coefficient of the ADC should not exceed
a.
± 200 µV/oC
b.
± 400 µV/oC
c.
± 600 µV/oC
d.
± 800 µV/oC
Answer:
Solution :
1998
1. The advantage of using a dual slope ADC in a digital
voltmeter is that
a.
Its conversion time is small
b.
Its accuracy is high
c.
It gives output in BCD format
d.
It does not require a comparator
Answer: B
2. The current I flowing through resistance ‘r’ in the circuit
shown is
a. -V/12R
b. V/12R
c. V/6R
d. V/3R
Answer: B
1999
1. The resolution of a 4 bit counting ADC is 0.5 volts. For an
analog input of 6.6 volts, the digital output of the ADC will be
a.
1011
b.
1101
c.
1100
d.
1110
Answer: D
2000
1. The number of comparators
in a 4 bit flash ADC is
a.
4
b.
5
c.
15
d.
16
Answer: C
2. An 8 bit successive approximation analog to digital
converter has full scale reading of 2.55 volts and its conversion time for an anlog
input of 1 volt is 20 µs. The conversion time for a 2 volts input is
a.
10 µs
b.
20 µs
c.
40 µs
d.
50 µs
Answer: B
3. The most commonly used
amplifier in sample and hold circuits is
a.
A unity gain inverting amplifier
b.
A unity gain non inverting amplifier
c.
An inverting amplifier with a gain
of 10
d.
An inverting amplifier with a gain
of 100
Answer: B
Solution :
4. For the 4 bit DAC shown, the output voltage Vo
is
a.
10 volts
b.
5 volts
c.
4 volts
d.
8 volts
Answer: B
2001
1. A monochrome video signal that ranges from 0 to 8 volts is
digitized using an 8-bit ADC.
a.
Determine the resolution of the ADC
in V/bit.
b.
Calculate the mean squared
quantization error.
c.
Suppose the ADC is counter
controlled. The counter is up counter and positive
edge triggered with clock frequency 1 MHz. What is the time taken in seconds to get a digital equivalent of 1.59
volts?
2002
1. The number of comparators required in a 3 bit comparator
type ADC is
a.
2
b.
3
c.
7
d.
8
Answer: C
2003
1. The minimum number of comparators required to build an 8 bit
flash ADC is
a.
8
b.
63
c.
255
d.
256
Answer: C
2. The circuit shown in the figure is a 4 bit DAC.
The input bits 0 and 1 are
represented by 0 volts and 5 volts respectively. The OP-AMP is ideal, but all
the resistances and the 5 volts inputs have a tolerance o f ± 10%. The
specification (rounded to the nearest multiple of 5%) for the tolerance of the
DAC is
a.
± 35%
b.
± 20%
c.
± 10%
d.
± 5%
2006
1. A 4 – bit D/A converter is connected to a free running 3 –
bit UP counter, as shown in the following figure. Which of the following
waveforms will be observed at Vo?
Answer: B
Solution : https://www.youtube.com/watch?v=U_Vz7cWzaog
2007
Statement for linked answer questions 1 & 2:
In the Digital to analog converter circuit shown in the
figure below, VR = 10 volts and R = 10 kΩ.
1. The current i is
a.
31.25 µA
b.
62.5 µA
c.
125 µA
d.
250 µA
Answer: B
2. The voltage Vo is
a.
– 0.781 volts
b.
– 1.562 volts
c.
– 3.125 volts
d.
– 6.250 volts
Answer: C
2008
Statement for Linked Answer Questions 1 and 2:
In the
following circuit, the comparator output is logic ‘1’ if V+ > V-
and is logic ‘0’
otherwise. The D/A conversion is done as per the relation.
The counter starts from the clear state.
1. The stable reading of the LED display is
a.
06
b.
07
c.
12
d.
13
Answer: D
2. The magnitude of the error
between VDAC and Vin at steady state in volts is
a.
0.2
b.
0.3
c.
0.5
d.
1.0
Answer: B
2011
1. The output of a 3 stage Johnson (twisted ring) counter is
fed to a digital to analog (D/A) converter as shown in the figure below. Assume
all states of the counter to be unset initially. The waveform which represents
the D/A converter output Vo is
Answer: A
Solution : https://www.youtube.com/watch?v=g9vVeVizDIM
2014
1. An analog voltage in the range 0 to 8 volts is divided in 16
equal intervals for conversion to 4 – bit digital output. The maximum
quantization error (in volts) is ………..
Answer: 0.25
Solution : https://www.youtube.com/watch?v=cH9U89uQWog
2. For a given sample and hold circuit, if the value of the
hold capacitor is increased, then
a.
Droop rate decreases and Acquisition
time decreases
b.
Droop rate decreases and Acquisition
time increases
c.
Droop rate increases and Acquisition
time decreases
d.
Droop rate increases and Acquisition
time increases
Answer: B
Solution : https://www.youtube.com/watch?v=hdo5X7vDKuc
Very informative n usefull thank you
ReplyDeletePlease update the questions after 2014
ReplyDeleteGreat help thanks sir
ReplyDeleteThank you very much
ReplyDeleteSir i want to create a website by using your link. please grant me permission
ReplyDeleteobtain a conversion sequence of a 4 bit successive approximation type adc to convert 12v into equivalent digital output
ReplyDeleteThnq sir .u r helpfull teacher .thn t thnq 😊
DeleteWhich of the following ADC has the highest conversion speed?
ReplyDeletei. Flash type
ii. Successive approximation
iii. Dual slope ADC
iv. Counter slope ADC
v. Conter- RAM type ADC
Plz slove this questions . it's very important questions .any sir solve this question.I want to jst reply .plz plz sir . because this question is my clge assignment .and ass8gnmass submission date of 13 may then jst fast solve the problem.
the ans is flash type ADC.
Deletethis is very helpful, thank you very much sir
ReplyDeleteConsider the 4-bit digital-to-analog converter shown in figure where the logic levels 0 and 1 are 0.4 V and 2.4 V respectively. The analog output 0() V for an input of 1001 is _______. [GATE 1995, IIT Kanpur}
ReplyDeletecan u help me for solving this?
my answer was 1.5 your?
Delete1. 55 An 8 bit Flash analog to digital converter has full scale reading of 2.55 V and its conversion
ReplyDeletetime for an analog input of 1V is 20µs. The conversion time for a 2V input will be
a) 10 µs b) 20 µs
c) 40 µs d) 50 µs