2. Solved Papers
  3. Manipal Engineering

Manipal Engineering Manipal Engineering Solved Paper-2011

  • question_answer
    At what temperature will the resistance of a copper wire become three times its value at \[0{}^\circ C\]? (temperature coefficient of resistance for copper = \[4\times {{10}^{-3}}{{/}^{0}}C\])

    A)  \[{{400}^{\text{o}}}C\]

    B)  \[{{450}^{\text{o}}}C\]

    C)  \[{{500}^{\text{o}}}C\]                

    D)         \[{{550}^{\text{o}}}C\]

    Correct Answer: C

    Solution :

    From definition of temperature resistance coefficient                 \[{{R}_{t}}={{R}_{0}}(1+\alpha t)\]                 \[3{{R}_{0}}={{R}_{0}}(1+4\times {{10}^{-3}}t)\]                 \[3=1+4\times {{10}^{-3}}t\]                 \[4\times {{10}^{-3}}t=2\]                 \[t=\frac{2}{4\times {{10}^{-3}}}\]                 \[={{500}^{o}}C\]


You need to login to perform this action.
You will be redirected in 3 sec spinner