McqMate
| 101. |
Which one of the following is NOT a valid rule of Boolean algebra? |
| A. | a = a\ |
| B. | aa = a |
| C. | a + 1 = 1 |
| D. | a + 0 = a |
| Answer» A. a = a\ | |
| 102. |
In the binary number ' 10011 ' the weight of the most significant digit is |
| A. | 2^4(2 raise to power 4) |
| B. | 2^3 (2 raise to power 3) |
| C. | 2^0 (2 raise to power 0) |
| D. | 2^1 (2 raise to power 1) |
| Answer» A. 2^4(2 raise to power 4) | |
| 103. |
The binary value ' 1010110 ' is equivalent to decimal |
| A. | 86 |
| B. | 87 |
| C. | 88 |
| D. | 89 |
| Answer» A. 86 | |
| 104. |
2's complement of hexadecimal number B70A is |
| A. | b70b |
| B. | b709 |
| C. | 48f6 |
| D. | 48f5 |
| Answer» C. 48f6 | |
| 105. |
2's complement of 5 is |
| A. | 1101 |
| B. | 1011 |
| C. | 1010 |
| D. | 1100 |
| Answer» B. 1011 | |
| 106. |
The 4-bit 2's complement representation of ' -7 ' is |
| A. | 111 |
| B. | 1111 |
| C. | 1001 |
| D. | 110 |
| Answer» C. 1001 | |
| 107. |
If we multiply ' 723 ' and ' 34 ' by representing them in floating point notation i.e. By first, converting them in floating point representation and then multiplying them, the value of mantissa of result will be |
| A. | 24.582 |
| B. | 2.4582 |
| C. | 24582 |
| D. | 0.24582 |
| Answer» A. 24.582 | |
| 108. |
The output of the expression F=A+B+C will be Logic when A=0, B=1, C=1. the symbol ' + ' here represents OR Gate. |
| A. | undefined |
| B. | one |
| C. | zero |
| D. | 10 (binary) |
| Answer» B. one | |
| 109. |
A NAND gate's output is LOW if |
| A. | all inputs are low |
| B. | all inputs are high |
| C. | any input is low |
| D. | any input is high |
| Answer» C. any input is low | |
| 110. |
NOR gate is formed by connecting |
| A. | or gate and then not gate |
| B. | not gate and then or gate |
| C. | and gate and then or gate |
| D. | or gate and then and gate |
| Answer» C. and gate and then or gate | |
| 111. |
The AND Gate performs a logical function |
| A. | addition |
| B. | subtraction |
| C. | multiplicatio |
| D. | division |
| Answer» C. multiplicatio | |
| 112. |
The Extended ASCII Code (American Standard Code for Information Interchange) is a code |
| A. | 2-bit |
| B. | 7-bit |
| C. | 8-bit |
| D. | 16-bit |
| Answer» C. 8-bit | |
| 113. |
The OR gate performs Boolean . |
| A. | multiplication |
| B. | subtraction |
| C. | division |
| D. | addition |
| Answer» D. addition | |
| 114. |
The output of an AND gate is one when |
| A. | all of the inputs are one |
| B. | any of the input is one |
| C. | any of the input is zero |
| D. | all the inputs are zero |
| Answer» A. all of the inputs are one | |
| 115. |
A NOR's gate output is HIGH if |
| A. | all inputs are high |
| B. | any input is high |
| C. | any input is low |
| D. | all inputs are low |
| Answer» D. all inputs are low | |
| 116. |
A logic circuit with an output X = A(Bar)BC+AB(Bar) consists of . |
| A. | two and gates, two or gates, two inverters |
| B. | three and gates, two or gates, one inverter |
| C. | two and gates, one or gate, two inverters |
| D. | two and gates, one or gate |
| Answer» C. two and gates, one or gate, two inverters | |
| 117. |
the boolean expression AB'CD'is |
| A. | a sumterm |
| B. | a product ter |
| C. | a literal ter |
| D. | m always 1 |
| Answer» B. a product ter | |
| 118. |
The boolean expression X = AB + CD represents |
| A. | two ors anded together |
| B. | a 4-input and gate |
| C. | two ands ored together |
| D. | an exclusive- or |
| Answer» C. two ands ored together | |
| 119. |
The expression is an example of Commutative Law for Multiplication. |
| A. | ab+c = a+bc |
| B. | a(b+c) = b(a+c) |
| C. | ab=ba |
| D. | a+b=b+a |
| Answer» C. ab=ba | |
| 120. |
The total amount of memory that is supported by any digital system depends upon |
| A. | the organization of memory |
| B. | the structure of memory |
| C. | the size of decoding unit |
| D. | the size of the address bus of the microproc essor |
| Answer» D. the size of the address bus of the microproc essor | |
| 121. |
Addition of two octal numbers “36” and “71” results in |
| A. | 213 |
| B. | 123 |
| C. | 127 |
| D. | 345 |
| Answer» C. 127 | |
| 122. |
In which of the following base systems is 123 not a valid number? |
| A. | base 10 |
| B. | base 16 |
| C. | base8 |
| D. | base 3 |
| Answer» D. base 3 | |
| 123. |
Storage of 1 KB means the following number of bytes |
| A. | 1000 |
| B. | 964 |
| C. | 1024 |
| D. | 1064 |
| Answer» D. 1064 | |
| 124. |
What is the octal equivalent of the binary number: 10111101 |
| A. | 675 |
| B. | 275 |
| C. | 572 |
| D. | 573 |
| Answer» B. 275 | |
| 125. |
The binary code of (21.125)10 is |
| A. | 10101.001 |
| B. | 10100.001 |
| C. | 10101.01 |
| D. | 10100.111 |
| Answer» A. 10101.001 | |
| 126. |
A NAND gate is called a universal logic element because |
| A. | it is used by everybody |
| B. | any logic function can be realized by nand gates alone |
| C. | all the minization techniques are applicable for optimum nand gate realization |
| D. | many digital computers use nand gates. |
| Answer» B. any logic function can be realized by nand gates alone | |
| 127. |
Digital computers are more widely used as compared to analog computers, because they are |
| A. | less expensive |
| B. | always more accurate and faster |
| C. | useful over wider ranges of problem types |
| D. | easier to maintain. |
| Answer» C. useful over wider ranges of problem types | |
| 128. |
Most of the digital computers do not have floating point hardware because |
| A. | floating point hardware is costly |
| B. | it is slower than software |
| C. | it is not possible to perform floating point addition by hardware |
| D. | of no specific reason. |
| Answer» A. floating point hardware is costly | |
| 129. |
The number 1000 would appear just immediately after |
| A. | ffff (hex) |
| B. | 1111 |
| C. | 7777 (octal) |
| D. | all of the |
| Answer» D. all of the | |
| 130. |
(1(10101)2 is |
| A. | (37)10 |
| B. | ( 69)10 |
| C. | (41 )10 |
| D. | — (5)10 |
| Answer» A. (37)10 | |
| 131. |
The number of Boolean functions that can be generated by n variables is equal to |
| A. | 2n |
| B. | 22 n |
| C. | 2n-1 |
| D. | — 2n |
| Answer» B. 22 n | |
| 132. |
Consider the representation of six-bit numbers by two’s complement, one’s
|
| A. | two’s complement only |
| B. | sign and magnitude and one’s complement only |
| C. | two’s complement and one’s complement only |
| D. | all three representa tions. |
| Answer» D. all three representa tions. | |
| 133. |
Positive logic in a logic circuit is one in which |
| A. | logic 0 and 1 are represented by 0 and positive voltage respectively |
| B. | logic 0 and, - 1 are represented by negative and positive voltages respectively |
| C. | logic 0 voltage level is higher than logic 1 voltage level |
| D. | logic 0 voltage level is lower than logic 1 voltage level. |
| Answer» D. logic 0 voltage level is lower than logic 1 voltage level. | |
| 134. |
Which of the following gate is a two-level logic gate |
| A. | or gate |
| B. | nand gate |
| C. | exclusive or gate |
| D. | not gate. |
| Answer» C. exclusive or gate | |
| 135. |
An AND gate will function as OR if |
| A. | all the inputs to the gates are “1” |
| B. | all the inputs are ‘0’ |
| C. | either of the inputs is “1” |
| D. | all the inputs and outputs are compleme nted. |
| Answer» D. all the inputs and outputs are compleme nted. | |
| 136. |
An OR gate has 6 inputs. The number of input words in its truth table are |
| A. | 6 |
| B. | 32 |
| C. | 64 |
| D. | 128 |
| Answer» C. 64 | |
| 137. |
NAND. gates are preferred over others because these |
| A. | have lower fabrication area |
| B. | can be used to make any gate |
| C. | consume least electronic power |
| D. | provide maximum density in a chip. |
| Answer» B. can be used to make any gate | |
| 138. |
In case of OR gate, no matter what the number of inputs, a |
| A. | 1 at any input causes the |
| B. | 1 at any input causes |
| C. | 0 any input causes the |
| D. | 0 at any input |
| Answer» A. 1 at any input causes the | |
| 139. |
Excess-3 code is known as |
| A. | weighted code |
| B. | cyclic |
| C. | self- |
| D. | algebraic |
| Answer» C. self- | |
| 140. |
Indicate which of the following three binary additions are correct? 1.1011 + 1010 = 10101
|
| A. | i and ii |
| B. | ii and iii |
| C. | iii only |
| D. | ii and i |
| Answer» D. ii and i | |
| 141. |
X – = Y + 1 means |
| A. | x = x – y + 1 |
| B. | x = –x – y – 1 |
| C. | x = –x + y + 1 |
| D. | x= x – y – 1 |
| Answer» A. x = x – y + 1 | |
| 142. |
A binary digit is called a |
| A. | bit |
| B. | byte |
| C. | number |
| D. | character |
| Answer» A. bit | |
| 143. |
The ASCII code for letter A is |
| A. | 1100011 |
| B. | 1111111 |
| C. | 1000001 |
| D. | 10011 |
| Answer» C. 1000001 | |
| 144. |
Transistor is a |
| A. | current controlled current device. |
| B. | current controlled voltage device. |
| C. | voltage controlled current device. |
| D. | voltage controlled voltage device. |
| Answer» A. current controlled current device. | |
| 145. |
A digital logic device used as a buffer should have what input/output characteristics? |
| A. | high input impedance and high output impedance |
| B. | low input impedance and high output impedance |
| C. | low input impedance and low output impedance |
| D. | high input impedance and low output impedance |
| Answer» D. high input impedance and low output impedance | |
| 146. |
What is the standard TTL noise margin? |
| A. | 5.0 v |
| B. | 0.2 v |
| C. | 0.8 v |
| D. | 0.4 v |
| Answer» D. 0.4 v | |
| 147. |
The range of a valid LOW input is: |
| A. | 0.0 v to 0.4 v |
| B. | 0.4 v to 0.8 v |
| C. | 0.0 v to 1.8 v |
| D. | 0.0 v to 2.8 v |
| Answer» B. 0.4 v to 0.8 v | |
| 148. |
When an IC has two rows of parallel connecting pins, the device is referred to as: |
| A. | a qfp |
| B. | a dip |
| C. | a phase splitter |
| D. | cmos |
| Answer» B. a dip | |
| 149. |
Which digital IC package type makes the most efficient use of printed circuit board space? |
| A. | smt |
| B. | to can |
| C. | flat pack |
| D. | dip |
| Answer» A. smt | |
| 150. |
The digital logic family which has minimum power dissipation is |
| A. | ttl |
| B. | rtl |
| C. | dtl |
| D. | cmos |
| Answer» D. cmos | |
| 151. |
Which of the following is the fastest logic |
| A. | ttl |
| B. | ecl |
| C. | cmos |
| D. | lsi |
| Answer» B. ecl | |
| 152. |
The digital logic family which has the lowest propagation delay time is |
| A. | ecl |
| B. | ttl |
| C. | cmos |
| D. | pmos |
| Answer» A. ecl | |
| 153. |
Which TTL logic gate is used for wired ANDing |
| A. | open collector output |
| B. | totem pole |
| C. | tri state output |
| D. | ecl gates |
| Answer» A. open collector output | |
| 154. |
CMOS circuits consume power |
| A. | equal to ttl |
| B. | less than ttl |
| C. | twice of ttl |
| D. | thrice of ttl |
| Answer» B. less than ttl | |
| 155. |
In a positive logic system, logic state 1 corresponds to |
| A. | positive voltage |
| B. | higher voltage level |
| C. | zero voltage level |
| D. | lower voltage level |
| Answer» B. higher voltage level | |
| 156. |
The commercially available 8-input multiplexer integrated circuit in the TTL family is |
| A. | 7495 |
| B. | 74153 |
| C. | 74154 |
| D. | 74151 |
| Answer» B. 74153 | |
| 157. |
The logic 0 level of a CMOS logic device is approximately |
| A. | 1.2 volts |
| B. | 0.4 volts |
| C. | 0volts |
| D. | 5volts |
| Answer» C. 0volts | |
| 158. |
Which ofthe following is a universal logic gate? |
| A. | or |
| B. | xor |
| C. | and |
| D. | nand |
| Answer» D. nand | |
| 159. |
How is the noise margin of a logic family defi ned? |
| A. | voh – vol |
| B. | greater of vdd – voh and vol – gnd |
| C. | smaller of vil – vol and voh – vih |
| D. | vih – vil. |
| Answer» C. smaller of vil – vol and voh – vih | |
| 160. |
What parameter causes the main limit on fan-out of CMOS logic in high-speed applications? |
| A. | d.c. input current |
| B. | output current |
| C. | input capacitance |
| D. | power supply voltage. |
| Answer» A. d.c. input current | |
| 161. |
The number of standard loads that the output of the gate can drive with out impairment of its normal operation is |
| A. | fan-in |
| B. | fan-out |
| C. | noise-margin |
| D. | power- dissipiatio n |
| Answer» B. fan-out | |
| 162. |
Measure of power consumed by the gate when fully driven by all its inputs is |
| A. | fan-in |
| B. | fan-out |
| C. | noise-margin |
| D. | power- dissipiatio n |
| Answer» D. power- dissipiatio n | |
| 163. |
Fan-out is specified in terms of |
| A. | voltage |
| B. | current |
| C. | watt |
| D. | unit load |
| Answer» D. unit load | |
| 164. |
Which of the following logic family has highest fan-out |
| A. | dtl |
| B. | cmos |
| C. | rtl |
| D. | ttl |
| Answer» B. cmos | |
| 165. |
Which of following consume minimum power |
| A. | ttl |
| B. | rtl |
| C. | dtl |
| D. | cmos |
| Answer» D. cmos | |
| 166. |
Among the logic families, low power dissipation is in |
| A. | dtl |
| B. | cmos |
| C. | rtl |
| D. | ttl |
| Answer» B. cmos | |
| 167. |
The temperature in which the performance of the IC is effective |
| A. | operating |
| B. | fan-out |
| C. | normal |
| D. | power- |
| Answer» A. operating | |
| 168. |
The nominal value of the dc supply voltage for TTL (transistor-transistor logic) devices is |
| A. | 0v |
| B. | 5v |
| C. | 10v |
| D. | 15v |
| Answer» B. 5v | |
| 169. |
The average transition delay time for the signal to propagate from input to output when the signals change in value. It is expressed in ns is |
| A. | propogation delay |
| B. | fan-out |
| C. | noise-margin |
| D. | power- dissipiatio n |
| Answer» A. propogation delay | |
| 170. |
the number of inputs connected to the gate without any degradation in the |
| A. | propogation delay |
| B. | fan-out |
| C. | fan- in |
| D. | power- dissipiatio |
| Answer» C. fan- in | |
| 171. |
Which of the following logic gives the complementary outputs? |
| A. | ecl |
| B. | ttl |
| C. | cmos |
| D. | pmos |
| Answer» A. ecl | |
| 172. |
The maximum noise voltage added to an input signal of a digital circuit |
| A. | fan-in |
| B. | fan-out |
| C. | noise-margin |
| D. | power- |
| Answer» C. noise-margin | |
| 173. |
Among the logic families, Slowest logic family is |
| A. | ttl |
| B. | rtl |
| C. | dtl |
| D. | cmos |
| Answer» D. cmos | |
| 174. |
Operating temperature of the IC vary from |
| A. | 0 to70 celsius |
| B. | 0to35celsius |
| C. | 0to 50celsius |
| D. | 0to70celsi |
| Answer» A. 0 to70 celsius | |
| 175. |
1. Open collector output 2. Totem-Pole Output 3. Tri-state output are the type of |
| A. | ttl logic |
| B. | rtl logic |
| C. | cmos logic |
| D. | none of this |
| Answer» A. ttl logic | |
| 176. |
If the channel is initially doped lightly with p-type impurity a conducting |
| A. | depletion |
| B. | enhancemen |
| C. | both mode |
| D. | none of |
| Answer» A. depletion | |
| 177. |
If the region beneath the gate is left initially uncharged the gate field must induce a
|
| A. | depletion mode operation mos |
| B. | enhancemen t mode operation of mos |
| C. | both mode |
| D. | none of this |
| Answer» B. enhancemen t mode operation of mos | |
| 178. |
The n- channel MOS conducts when its |
| A. | gate- to- source voltage |
| B. | gate- to- source |
| C. | gate- to- source |
| D. | none of this |
| Answer» A. gate- to- source voltage | |
| 179. |
The p- channel MOS conducts when its |
| A. | gate- to- |
| B. | gate- to- |
| C. | gate- to- |
| D. | none of |
| Answer» C. gate- to- | |
| 180. |
The fan-out of a MOS-logic gate is higher than that of TTL gates because of its |
| A. | low input impedance |
| B. | high input impedance |
| C. | low output impedance |
| D. | high output impedance |
| Answer» D. high output impedance | |
| 181. |
Which factor does not affect CMOS loading? |
| A. | charging time associated |
| B. | discharging time |
| C. | output capacitance |
| D. | input capacitanc |
| Answer» C. output capacitance | |
| 182. |
Logic gates are the basic elements that make a |
| A. | analog system |
| B. | basic system |
| C. | gating system |
| D. | digital system |
| Answer» D. digital system | |
| 183. |
Which of the following gate is a two-level logic gate |
| A. | or gate |
| B. | nand gate |
| C. | exclusive or gate |
| D. | not |
| Answer» C. exclusive or gate | |
| 184. |
Among the logic families, the family which can be used at very high frequency greater than 100 MHz in a 4 bit |
| A. | ttlas |
| B. | cmos |
| C. | ecl |
| D. | ttlls |
| Answer» C. ecl | |
| 185. |
The fan Out of a 7400 NAND gate is |
| A. | 2ttl |
| B. | 5ttl |
| C. | 8ttl |
| D. | 10ttl |
| Answer» D. 10ttl | |
| 186. |
Which transistor element is used in CMOS logic? |
| A. | fet |
| B. | mosfet |
| C. | bipolar |
| D. | unijunctio n |
| Answer» B. mosfet | |
| 187. |
CMOS circuits are extensively used for ON-chip computers mainly because of their extremely |
| A. | low power dissipation. |
| B. | high noise immunity. |
| C. | large packing density. |
| D. | low cost. |
| Answer» C. large packing density. | |
| 188. |
Which equation is correct? |
| A. | vnl = vil(max) + vol(max) |
| B. | vnh = voh(min) + vih(min) |
| C. | vnl = voh(min) – vih(min) |
| D. | vnh = voh(min) – vih(min) |
| Answer» D. vnh = voh(min) – vih(min) | |
| 189. |
The greater the propagation delay, the |
| A. | lower the maximum frequency |
| B. | higher the maximum frequency |
| C. | maximum frequency is unaffected |
| D. | minimum frequency is unaffected |
| Answer» A. lower the maximum frequency | |
| 190. |
For a CMOS gate, which is the best speed-power product? |
| A. | 1.4 pj |
| B. | 1.6 pj |
| C. | 2.4 pj |
| D. | 3.3 pj |
| Answer» A. 1.4 pj | |
| 191. |
In a TTL circuit, if an excessive number of load gate inputs are connected, |
| A. | voh(min) drops below voh |
| B. | voh drops below voh(min) |
| C. | voh exceeds voh(min) |
| D. | voh and voh(min) are unaffected |
| Answer» B. voh drops below voh(min) | |
| 192. |
Which is not a MOSFET terminal? |
| A. | gate |
| B. | drain |
| C. | source |
| D. | base |
| Answer» D. base | |
| 193. |
An open-drain gate is the CMOS counterpart of |
| A. | an open- collector ttl gate |
| B. | a tristate ttl gate |
| C. | a bipolar junction transistor |
| D. | an emitter- coupled logic gate |
| Answer» A. an open- collector ttl gate | |
| 194. |
The active switching element used in all TTL circuits is the |
| A. | bipolar junction transistor (bjt |
| B. | field-effect transistor (fet |
| C. | metal-oxide semiconduct or field- effect transistor (mosfet |
| D. | unijunctio n transistor (uj) |
| Answer» A. bipolar junction transistor (bjt | |
| 195. |
One output structure of a TTL gate is often referred to as a |
| A. | diode |
| B. | jbt arrangement |
| C. | totem-pole arrangement |
| D. | base, emitter, collector arrangeme nt |
| Answer» C. totem-pole arrangement | |
| 196. |
An open-collector output requires |
| A. | a pull-down resistor |
| B. | a pull-up resistor |
| C. | no output resistor |
| D. | an output resistor |
| Answer» B. a pull-up resistor | |
| 197. |
Which is not an output state for tristate logic? |
| A. | high |
| B. | low |
| C. | high-z |
| D. | low-z |
| Answer» D. low-z | |
| 198. |
TTL is alive and well, particularly in |
| A. | industrial applications |
| B. | millitary applications |
| C. | educational applications |
| D. | commercia lapplicatio ns |
| Answer» C. educational applications | |
| 199. |
A TTL NAND gate with IIL(max) of –1.6 mA per input drives eight TTL inputs. How much current does the drive output sink? |
| A. | –12.8 ma |
| B. | –8 ma |
| C. | –1.6 ma |
| D. | –25.6 ma |
| Answer» A. –12.8 ma | |
| 200. |
A standard TTL circuit with a totem-pole output can sink, in the LOW state (IOL(max)), |
| A. | 16 ma |
| B. | 20 ma |
| C. | 24 ma |
| D. | 28ma |
| Answer» A. 16 ma | |
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