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Manipal MET2023PhysicsCurrent Electricity

The resistance of a wire at 20^ C is 20 and at 500^ C is 60 . At which temperature its resistance will be 25 ?

Options

  1. A50^ C
  2. B60^ C
  3. C70^ C
  4. D80^ C

Correct answer

D. 80^ C

Step-by-step solution

Resistance, R_t=R₀(1+ t)20=R₀(1+20 ) and 60=R₀(1+500 ) From this equation, we can find aligned R₀ & =18.33 & =4.54 10⁻³ R_t & =25 aligned aligned & Again, R_t=R₀(1+ t) & 25=18.33 (1+4.54 10⁻³ t ) aligned We find t=80^ C

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