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GATE CSE 2017 Set 2 · Q34

MCQ2 marksEasy

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Consider a binary code that consists of only four valid codewords as given below: 00000,01011,10101,1111000000, 01011, 10101, 11110 Let the minimum Hamming distance of the code be pp and the maximum number of erroneous bits that can be corrected by the code be qq. Then the values of pp and qq are

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Solution

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Official answer: A) p=3 and q=1

Data Link Layer

Given the set of codewords C={00000,01011,10101,11110}C = \{00000, 01011, 10101, 11110\}:

  1. Calculate the Hamming distance d(ci,cj)d(c_i, c_j) between every pair of distinct codewords:

    • d(00000,01011)=3d(00000, 01011) = 3

    • d(00000,10101)=3d(00000, 10101) = 3

    • d(00000,11110)=4d(00000, 11110) = 4

    • d(01011,10101)=4d(01011, 10101) = 4

    • d(01011,11110)=3d(01011, 11110) = 3

    • d(10101,11110)=3d(10101, 11110) = 3

    The minimum Hamming distance is:

    p=dmin⁡=3p = d_{\min} = 3
  2. The relationship between the minimum Hamming distance dmin⁡d_{\min} and the error-correcting capability qq is:

    dmin⁡≥2q+1d_{\min} \ge 2q + 1
    3≥2q+1  ⟹  2q≤2  ⟹  q=13 \ge 2q + 1 \implies 2q \le 2 \implies q = 1

Therefore, p=3p = 3 and q=1q = 1, which corresponds to option (A).

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This Data Link Layer previous year question is Q34 of the GATE CSE 2017 Set 2 paper. Find more GATE CSE PYQs on Data Link Layer in Computer Networks, or browse all GATE CSE PYQs.

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Data Link Layer in GATE CSE

Data Link Layer has 27 GATE CSE PYQs across 17 papers from 2013 to 2026. 10 of them are 2-mark MCQs like this one, and it is the only one in GATE CSE 2017 Set 2.

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GateAI solution cardGATE CSE 2017 Set 2 · Q34 · MCQ

Consider a binary code that consists of only four valid codewords as given below: 00000, 01011, 10101, 11110 Let the minimum Hamming distance of the code be p and the maximum number of erroneous bits that can be corrected by the code be q. Then the values of p and q are

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