Number Systems and Codes Questions and Answers

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Number Systems and Codes Questions with Answers form the foundation of digital electronics reasoning and aptitude exams. This topic includes binary, octal, decimal, and hexadecimal number conversions, along with coding systems like Gray, ASCII, and BCD. Competitive exams such as GATE, DRDO, and ISRO often test candidates’ logical understanding of number representation and digital computation. Practicing reasoning questions and answers with step-by-step solutions builds numerical reasoning and circuit analysis confidence. Each question is structured to test clarity on base conversions, weighted codes, and arithmetic operations. With these aptitude-based questions, you can easily master the numerical logic behind digital systems. Download the PDF and start your reasoning test practice online today.

Number Systems and Codes

Showing 10 of 146 questions

21. The binary number for octal 458 is ________.

  • 100010
  • 100101
  • 110101
  • 100100
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22. The sum of 11101 + 10111 equals ________.

  • 110011
  • 100001
  • 110100
  • 100100
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23. Convert the following binary number to decimal. 100110102

  • 154
  • 155
  • 153
  • 157
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24. The decimal number 188 is equal to the binary number ________.

  • 10111100
  • 0111000
  • 1100011
  • 1111000
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25. Convert the following binary number to octal. 0011010112

  • 1538
  • 3518
  • 2538
  • 3528
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26. How many bits are in an ASCII character?

  • 16
  • 8
  • 7
  • 4
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27. A binary number's value changes most drastically when the ________ is changed.

  • MSB
  • frequency
  • LSB
  • duty cycle
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28. Convert decimal 213 to binary.

  • 11001101
  • 11010101
  • 01111001
  • 11100011
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29. The decimal number for octal 748 is ________.

  • 74
  • 60
  • 22
  • 62
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30. The sum of the two BCD numbers, 0011 + 0011, is ________.

  • 0110
  • 0111
  • 0011
  • 1100
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