Multiple choice question for engineering
Set 1
1. BiCMOS is an evolved semiconductor technology that integrates two formerly separate semiconductor technologies those of the
a) CMOS and FET
b) MOSFET and CMOS
c) BJT and CMOS
d) BJT and MOSFET
Answer
Answer: c [Reason:] BiCMOS is an evolved semiconductor technology that integrates two formerly separate semiconductor technologies those of the BJT and CMOS.
2. We use BJT in BiCMOS because of its
a) High speed
b) High gain
c) Low output resistance
d) All of the Mentioned
Answer
Answer: d [Reason:] Bipolar junction transistors offer high speed, high gain and low output resistance, which are excellent properties for high-frequency analog amplifiers.
3. We use CMOS transistor in BiCMOS because of its
a) High input resistance
b) Simple construction
c) Low power logic gates
d) All of the Mentioned
Answer
Answer: d [Reason:] CMOS technology offers high input resistance and is excellent for constructing simple, low-power logic gates.
4. When was BiCMOS technology introduced?
a) 1990
b) 1991
c) 1992
d) 1989
Answer
Answer: a [Reason:] BiCMOS technology was introduced in 1990s.
5. On which technology the Pentium is based?
a) MOSFET
b) CMOS
c) BiCMOS
d) None of the Mentioned
Answer
Answer: c [Reason:] The Pentium technology is based on BiCMOS technology because BiCMOS circuits use the characteristics of each type of transistor most appropriately.
6. The advantage of BiCMOS circuit is that it gives
a) Large fan-out
b) Large fan-in
c) Small fan-in
d) Small fan-out
Answer
Answer: a [Reason:] BiCMOS circuits are particularly useful for logic with large fan-out (large capacitive load).
7. How many members a BiCMOS family have?
a) 5
b) 6
c) 7
d) 8
Answer
Answer: a [Reason:] The BiCMOS family has mainly 5 members and those are ABT logic, ALB logic, ALVT logic, BCT logic and LVT logic.
8. What is LVT logic?
a) Lower threshold voltage
b) Lower supply threshold voltage
c) Lower supply voltage while retaining TTL logic levels
d) All of the Mentioned
Answer
Answer: c [Reason:] LVT logic is nothing but the lower supply voltage while retaining TTL logic levels.
9. What does ALVT mean?
a) All lower supply voltage while retaining TTL logic levels
b) ABT lower supply voltage while retaining TTL logic levels
c) Advanced version of LVT logic
d) None of the Mentioned
Answer
Answer: c [Reason:] ALVT means an ‘advanced’ version of LVT logic.
10. The full form of PTL is
a) Pull transistor logic
b) Push transistor logic
c) Pass transistor logic
d) None of the Mentioned
Answer
Answer: c [Reason:] The full form of PTL is “pass transistor logic”.
11. CVSL means
a) Cascode Voltage Switch Logic
b) Cascade Voltage Switch Logic
c) Complementary Voltage Switch Logic
d) None of the Mentioned
Answer
Answer: c [Reason:] Cascode Voltage Switch Logic (CVSL) refers to a CMOS-type logic family which is designed for certain advantages. It requires mainly N-channel MOSFET transistors to implement the logic using true and complementary input signals and also needs two P-channel transistors at the top to pull one of the outputs high.
Set 2
1. Binary coded decimal is a combination of
a) Two binary digits
b) Three binary digits
c) Four binary digits
d) None of the Mentioned
Answer
Answer: c [Reason:] Binary coded decimal is a combination of 4 binary digits. For example-8421.
2. The decimal number 10 is represented in its BCD form as
a) 1010
b) 01010
c) 00010000
d) 001010
Answer
Answer: c [Reason:] The decimal number 10 is represented in its BCD form as 0001 0000.
3. Add the two BCD numbers: 1001 + 0100 = ?
a) 1101
b) 00001101
c) 00110011
d) None of the mentioned
Answer
Answer: c [Reason:] Firstly, Add the 1001 and 0100. We get 1101 as output but it’s not in BCD form. So, we add 0110 (i.e. 6) with 1101. As a result we get 10011 and it’s BCD form is 0001 0011.
4. Carry out BCD subtraction for (68) – (61) using 10’s complement method.
a) 00000111
b) 01110000
c) 100000111
d) 011111000
Answer
Answer: a
5. Code is a symbolic representation of __________ information.
a) Continuous
b) Discrete
c) binary
d) None of the Mentioned
Answer
Answer: b [Reason:] Code is a symbolic representation of discrete information, which may be present in the form of numbers, letters or physical quantities.
6. When numbers, letters or words are represented by a special group of symbols, this process is called
a) Decoding
b) Encoding
c) Coding
d) None of the Mentioned
Answer
Answer: b [Reason:] When numbers, letters or words are represented by a special group of symbols, this process is called encoding. Encoding in the sense of fetching the codes or words in a computer.
7. A three digit decimal number requires ________ for representation in the conventional BCD format.
a) 3 bits
b) 6 bits
c) 12 bits
d) 24 bits
Answer
Answer: c [Reason:] The number of bits needed to represent a given decimal number is always greater than the number of bits required for a straight binary encoding of the same. Hence, a three digit decimal number requires 12 bits for representation in BCD format.
8. How many bits would be required to encode decimal numbers 0 to 9999 in straight binary codes.
a) 12
b) 14
c) 16
d) 18
Answer
Answer: c [Reason:] Total number of decimals to be represented = 10000 = 10^4 = 2^13.29. Therefore, the number of bits required for straight binary encoding = 14.
9. The excess-3 code for 597 is given by
a) 100011001010
b) 100010100111
c) 010110010111
d) 010110101101
Answer
Answer: a [Reason:] The addition of ‘3’ to each digit yields the three new digits ‘8’, ’12’ and ’10’. Hence, the corresponding four-bit binary equivalents are 100011001010.
10. The decimal equivalent of the excess-3 number 110010100011.01110101 is
a) 970.42
b) 1253.75
c) 861.75
d) None of the Mentioned
Answer
Answer: a [Reason:] The conversion of binary numbers into digits ‘1100’, ‘1010’, ‘0011’, ‘0111’ and ‘0101’ gives ’12’, ‘5’, ‘3’, ‘7’ and ‘5’ respectively. Hence, the decimal number is 970.42.
Set 3
1. In boolean algebra, the OR operation is performed by which properties?
a) Associative properties
b) Commutative properties
c) Distributive properties
d) All of the Mentioned
Answer
Answer: d [Reason:] The expression for Associative property is given by A+(B+C) = (A+B)+C & A*(B*C) = (A*B)*C.
The expression for Commutative property is given by A+B = B+A & A*B = B*A.
The expression for Distributive property is given by A+BC=(A+B)(A+C) & A(B+C) = AB+AC.
2. The expression for Absorption law is given by
a) A+AB = A
b) A+AB = B
c) AB+AA’ = A
d) None of the Mentioned
Answer
Answer: a [Reason:] The expression for absorption law is given by – A+AB = A.
3. According to boolean law: A + 1 = ?
a) 1
b) A
c) 0
d) A’
Answer
Answer: a [Reason:] A + 1 = A.
4. The involution of A is equal to
a) A
b) A’
c) 1
d) 0
Answer
Answer: a [Reason:] The involution of A means double inversion of A(i.e. A”) and is equal to A.
5. A(A + B) = ?
a) AB
b) 1
c) (1 + AB)
d) A
Answer
Answer: d [Reason:] A(A + B) = AA + AB = A + AB = A(1 + B) = A*1 = A.
6. DeMorgan’s theorem states that
a) (AB)’ = A’ + B’
b) (A + B)’ = A’ * B
c) A’ + B’ = A’B’
d) None of the Mentioned
Answer
Answer: a [Reason:] The DeMorgan’s law states that (AB)’ = A’ + B’ & (A + B)’ = A’ * B’.
7. (A + B)(A’ * B’) = ?
a) 1
b) 0
c) AB
d) AB’
Answer
Answer: b [Reason:] (A + B)(A’ * B’) = AA’B’ + BA’B’ = 0 + BB’A’ = 0 + 0 = 0 (AA’ = BB’ = 0).
8. Complement of the expression A’B + CD’ is
a) (A’ + B)(C’ + D)
b) (A + B’)(C’ + D)
c) (A’ + B)(C’ + D)
d) (A + B’)(C + D’)
Answer
Answer: b [Reason:] (A’B + CD’)’ = (A’B)'(CD’)’ = (A” + B’)(C’ + D”) = (A + B’)(C’ + D).
9. Simplify Y = AB’ + (A’ + B)C
a) AB’ + C
b) AB + AC
c) A’B + AC’
d) AB + A
Answer
Answer: a [Reason:] Y = AB’ + (A’ + B)C = AB’ + (A’ + B)C = AB’ + (AB’)’C = AB’ + C.
10. The boolean function A + BC is a reduced form of
a) AB + BC
b) (A + B)(A + C)
c) A’B + AB’C
d) (A + C)B
Answer
Answer: b [Reason:] (A + B)(A + C) = AA + AC + AB + BC = A + AC + AB + BC = A(1 + C + B) + BC = A + BC.
Set 4
1. The full form of CMOS is
a) Capacitive metal oxide semiconductor
b) Capacitive metallic oxide semiconductor
c) Complementary metal oxide semiconductor
d) None of the Mentioned
Answer
Answer: c [Reason:] The full form of CMOS is complementary metal oxide semiconductor.
2. The full form of COS-MOS is
a) Complementary symmetry metal oxide semiconductor
b) Complementary systematic metal oxide semiconductor
c) Capacitive symmetry metal oxide semiconductor
d) None of the Mentioned
Answer
Answer: a [Reason:] The full form of COS-MOS is complementary systematic metal oxide semiconductor.
3. CMOS is also sometimes referred to as
a) Capacitive metal oxide semiconductor
b) Capacitive symmetry metal oxide semiconductor
c) Complementary symmetry metal oxide semiconductor
d) None of the Mentioned
Answer
Answer: c [Reason:] CMOS is also sometimes referred to as complementary systematic metal oxide–semiconductor (COS-MOS).
4. CMOS technology is used in
a) Inverter
b) Microprocessor
c) Digital logic
d) Both microprocessor and digital logic
Answer
Answer: d [Reason:] CMOS technology is used in Microprocessor, Microcontroller, static RAM and other digital logic circuits. CMOS technology is also used for several analog circuits such as image sensors (CMOS sensor), data converters and highly integrated transceivers for many types of communication.
5. Two important characteristics of CMOS devices are
a) High noise immunity
b) Low static power consumption
c) High resistivity
d) Both high noise immunity and low static power consumption
Answer
Answer: d [Reason:] Two important characteristics of CMOS devices are high noise immunity and low static power consumption. Since one transistor of the pair is always off and the series combination draws significant power only momentarily during switching between on and off states. Consequently, CMOS devices do not produce as much waste heat as other forms of logic, for example transistor–transistor logic (TTL) or NMOS logic which normally have some standing current even when not changing state.
6. CMOS behaves as a/an
a) Adder
b) Subtracter
c) Inverter
d) Comparator
Answer
Answer: c [Reason:] Since, the outputs of the PMOS and NMOS transistors are complementary such that when the input is low, the output is high and when the input is high, the output is low. Because of this behaviour of input and output, the CMOS circuit’s output is the inverse of the input.
7. An important characteristic of a CMOS circuit is the
a) Noise immunity
b) Duality
c) Symmetricity
d) None of the Mentioned
Answer
Answer: b [Reason:] An important characteristic of a CMOS circuit is the duality that exists between its PMOS transistors and NMOS transistors.
8. CMOS logic dissipates _______ power than NMOS logic circuits
a) More
b) Less
c) Equal
d) None of the Mentioned
Answer
Answer: b [Reason:] CMOS logic dissipates less power than NMOS logic circuits because CMOS dissipates power only when switching (“dynamic power”).
9. Semiconductors are made of
a) Ge and Si
b) Si and Pb
c) Ge and Pb
d) None of the Mentioned
Answer
Answer: a [Reason:] Semiconductors are made of Silicon (Si) and Germanium (Ge).
10. Which chip was the first RTC and CMOS RAM chip to be used in early IBM computers, capable of storing a total of 64 bytes?
a) The Samsung 146818
b) The Samsung 146819
c) The Motorola 146818
d) The Motorola 146819
Answer
Answer: c [Reason:] The Motorola 146818 was the first RTC and CMOS RAM chip to be used in early IBM computers; capable of storing a total of 64 bytes.
Set 5
1. A code converter is a logic circuit that
a) Inverts the given input
b) Converts into decimal number
c) Converts data of one type into another type
d) None of the Mentioned
Answer
Answer: c [Reason:] A code converter is a logic circuit that changes data presented in one type of binary code to another type of binary code.
2. Use the weighting factors to convert the following BCD numbers to binary:
0101 0011 & 0010 0110 1000
a) 01010011 001001101000
b) 11010100 100001100000
c) 110101 100001100
d) 101011 001100001
Answer
Answer: c [Reason:] Firstly, convert every 4 sets of binary to decimal from the given: 0101=5, 0011=3. Then convert 53 to decimal, which will give 110101. Again, do the same with the next 4 set of binary digits.
3. The primary use for Gray code is
a) Coded representation of a shaft’s mechanical position
b) Turning on/off software switches
c) To represent the correct ASCII code to indicate the angular position of a shaft on rotating machinery
d) To convert the angular position of a shaft on rotating machinery into hexadecimal code
Answer
Answer: a [Reason:] Gray code is useful because only one bit changes at a time, which is implemented easily in Coded representation of a shaft’s mechanical position.
4. Code is a symbolic representation of
a) Continuous information
b) Discrete information
c) Decimal information into binary
d) Binary information into decimal
Answer
Answer: a [Reason:] Code is a symbolic representation of discrete information. Since, codes are nothing but a particular number, which is in integral form.
5. One way to convert BCD to binary using the hardware approach is
a) With MSI IC circuits
b) With a keyboard encoder
c) With an ALU
d) UART
Answer
Answer: a [Reason:] One way to convert BCD to binary using the hardware approach is MSI IC (i.e. medium scale integration) circuits.
6. Why is the Gray code more practical to use when coding the position of a rotating shaft?
a) All digits change between counts
b) Two digits change between counts
c) Only one digit changes between counts
d) None of the Mentioned
Answer
Answer: c [Reason:] The Gray code is more practical to use when coding the position of a rotating shaft because only one digit changes between counts that is reflected to the next count.
7. Reflected binary code is also known as
a) BCD code
b) Binary code
c) ASCII code
d) Gray Code
Answer
Answer: d [Reason:] The reflected binary code is also known as gray code because one digit reflected to the next bit.
8. Why do we use gray codes?
a) To count the no of bits changes
b) To rotate a shaft
c) Error correction
d) None of the Mentioned
Answer
Answer: c [Reason:] Today, Gray codes are widely used to facilitate error correction in digital communications such as digital terrestrial television and some cable TV systems.
9. Earlier, reflected binary codes were applied to
a) Binary addition
b) 2’s complement
c) Mathematical puzzles
d) binary multiplication
Answer
Answer: c [Reason:] Reflected binary codes were applied to mathematical puzzles before they became known to engineers.
10. The binary representation of BCD number 00101001 (decimal 29) is
a) 0011101
b) 0110101
c) 1101001
d) 0101011
Answer
Answer: a [Reason:] The given BCD number 00101001 has three 1s. So, it can be rewritten as 0000001-1, 0001000-8, 0010100-20 and after addition, we get 0011101 as output.
11. Convert binary number into gray code: 100101
a) 101101
b) 001110
c) 110111
d) 111001
Answer
Answer: c [Reason:] Conversion of binary number 100101 into gray code takes place in this way: Firstly, write the 1st digit as it is from left; now add the two numbers sequentially.