Digital Electronics/Circuits Multiple Choice Questions on “Code Converters”.
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. Converts to octal
Answer: C
Clarification: 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: C
Clarification: Firstly, convert every 4 sets of binary to decimal from the given: 0101=5, 0011=3. Then convert 53 to binary, 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: A
Clarification: 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. In Gray Code, every sequence of successive bits differs by 1 bit only.
4. Code is a symbolic representation of ___________
A. Discrete information
B. Continuous information
C. Decimal information into binary
D. Binary information into decimal
Answer: A
Clarification: Code is a symbolic representation of discrete information. Codes can be anything like numbers, letter or words, written in terms of group of symbols.
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: A
Clarification: 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. Alternate digit changes between counts
Answer: C
Clarification: 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: D
Clarification: The reflected binary code is also known as gray code because one digit reflected to the next bit. In Gray Code, every sequence of successive bits differs by 1 bit only.
8. Why do we use gray codes?
A. To count the no of bits changes
B. To rotate a shaft
C. Error correction
D. Error Detection
Answer: C
Clarification: 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: C
Clarification: The reflected binary code is also known as gray code because one digit reflected to the next bit. In Gray Code, every sequence of successive bits differs by 1 bit only. 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: A
Clarification: 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: C
Clarification: : Conversion from Binary To Gray Code:
1 (XOR) 0 (XOR) 0 (XOR) 1 (XOR) 0 (XOR) 1
↓ ↓ ↓ ↓ ↓
1 1 0 1 1 1