250+ TOP MCQs on Parity Generators/Checkers – 1 and Answers

Digital Electronics/Circuits Multiple Choice Questions on “Parity Generators/Checkers – 1”.

1. How many outputs are present in a BCD decoder?
A. 4
B. 5
C. 15
D. 10
Answer: D
Clarification: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2ⁿ outputs. A BCD to Decimal decoder has 10 number of outputs because the decimal digit’s range is from 0 to 9.

2. Which digital system translates coded characters into a more useful form?
A. Encoder
B. Display
C. Counter
D. Decoder
Answer: D
Clarification: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2ⁿ outputs. Decoder converts the coded characters into our required data form.

3. What control signals may be necessary to operate a 1-line-to-16 line decoder?
A. Flasher circuit control signal
B. A LOW on all gate enable inputs
C. Input from a hexadecimal counter
D. A HIGH on all gate enable circuits
Answer: B
Clarification: A LOW on all gate enable inputs is necessary to operate a 1-line-to-16 line decoder because enable pins are usually, active-low pins.

4. How many inputs are required for a 1-of-10 BCD decoder?
A. 4
B. 8
C. 10
D. 2
Answer: A
Clarification: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2ⁿ outputs. Therefore, for a BCD to decimal decoder, No. of inputs = 4 such that number of outputs is <= 2ⁿ.

5. A BCD decoder will have how many rows in its truth table?
A. 10
B. 9
C. 8
D. 3
Answer: A
Clarification: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2ⁿ outputs. Thus, BCD decoder will have 10 rows as it’s input ranges from 0 to 9.

6. How many possible outputs would a decoder have with a 6-bit binary input?
A. 32
B. 64
C. 128
D. 16
Answer: C
Clarification: The possible outputs would be: 2ⁿ = 64 (Since n = 6 here).

7. Which is the way to convert BCD to binary using the hardware approach?
A. By using MSI IC circuits
B. By using a keyboard encoder
C. By using an ALU
D. By using UART
Answer: A
Clarification: One way to convert BCD to binary using the hardware approach is MSI (medium scale integration) IC circuits.

8. How many inputs are required for a 1-of-16 decoder?
A. 2
B. 16
C. 8
D. 4
Answer: D
Clarification: A binary decoder is a combinational logic circuit which decodes binary information from n-inputs to a maximum of 2ⁿ outputs. Here, number of outputs = 16.
16 = 2⁴ = 2ⁿ. Thus, number of inputs is 4.

9. A truth table with output columns numbered 0–15 may be for which type of decoder IC?
A. Hexadecimal 1-of-16
B. Dual octal outputs
C. Binary-to-hexadecimal
D. Hexadecimal-to-binary
Answer: A
Clarification: A binary decoder is a combinational logic circuit that decodes binary information from n-inputs to a maximum of 2ⁿ outputs. A truth table with output columns numbered 0–15 may be for Hexadecimal 1-of-16. Because hexadecimal occupies less space in a system.

10. How can the active condition (HIGH or LOW) or the decoder output be determined from the logic symbol?
A. A bubble indicates active-HIGH
B. A bubble indicates active-LOW
C. A triangle indicates active-HIGH
D. A triangle indicates active-LOW
Answer: B
Clarification: A bubble indicates active-LOW in a decoder always. Enable pin of the decoder is usually active-LOW and is triggered on the input being at 0.