Determine the resistance and temperature-coefficient:

A platinum coil has a resistance of 3.146 Ω at 40^oC and 3.767 Ω at 100^oC. Determine the resistance at 0^oC and the temperature-coefficient of resistance at 40^oC.

Solution

R_t  = R₀  + α₀  R₀  (t - t₀ )

Take t0 = initial temperature = 0^o.

R_t  = R₀  + α₀  t R₀

= R₀ (1 + α₀ t )

R₁₀₀ = R₀ (1 + 100 α₀) at          t = 100 C          ------- (i)

 

And        R₄₀ = R₀ (1 + 40 α₀ )         at  t = 40^oC           ----------  (ii)

From Eqs. (i) and (ii)

3.767 /3.146    = 1 + 100 α₀/1 + 40 α₀   ⇒ α = 0.00379 per^o C

From Eq. (i)

∴ 3.767 = R₀  (1 + 100 × 0.00379)

R₀ = 2.732,

α₄₀ =   1/( (1/ α₀) + (t₂  - t₁ ) =1/ (1/0.00379) + (40 - 0) = 1/304 per  ^o C

Posted Date: 2/4/2013 3:07:39 AM | Location : United States

Ask an Expert

Related Discussions:- Determine the resistance and temperature-coefficient, Assignment Help, Ask Question on Determine the resistance and temperature-coefficient, Get Answer, Expert's Help, Determine the resistance and temperature-coefficient Discussions

Write discussion on Determine the resistance and temperature-coefficient
Your posts are moderated

Write your message here..

Related Questions

Determine the total energy loss, Determine the total energy loss: Two ... Determine the total energy loss: Two capacitors C 1 = 50 μF and C 2 = 100 μF are connected in parallel across 250 V supply. Determine the total energy loss. Figure

What do you mean by waveforms, Q. What do you mean by Waveforms? We are... Q. What do you mean by Waveforms? We are often interested in waveforms, which may not be constant in time of particular interest is a periodic waveform, which is a time-varying

Multiprogramming - single processor one users many program, Multiprogramm... Multiprogramming - Single Processor one Users  Many  Programs When single  processor is  used to execute more than  one independent program simultaneously the technique  is ca

Switching characteristics , Switching Characteristics The switching  c... Switching Characteristics The switching  characteristics of power MOSFET the delay time and rise time are responsible to remove the  effect of internal capacitance of the devi

8 bit data to register - move immediate instruction , 8 bit  data to Regi... 8 bit  data to Register   This form  of the  instruction is used to copy 8 bit  data directly  to the register  location specified in  the instruction. The  instruction format i

Measure phase angle by using an oscilloscope, 1. Introduction : ... 1. Introduction : Theory:  Phase angle is defined as the number of degrees separating two sine waves of the same frequency. The Phase shift is defined as any change t

Calculate the diameter of an air-filled circular waveguide, Q. Calculate th... Q. Calculate the diameter of an air-filled circular waveguide? Unlike transmission lines, which operate at any frequency up to a cutoff value, waveguides have both upper and lo

Explain the types of coupling, Problem : a) What is the definition of E... Problem : a) What is the definition of Electromagnetic Compatibility (EMC) according to the International Electrotechnical Commission (IEC) and why is it gaining increasing imp

Electronics, The mobility of free electrons and holes for pure silicon are ... The mobility of free electrons and holes for pure silicon are 0.13 and 0.05 m2/V-S respectively. Find the intrinsic conductivity for silicon. Assuming ni = 1.5x 1016/cm3 at room te

In what way is program control superior to wired control, Q. Classify switc... Q. Classify switching systems. In what way is stored program control superior to hard wired control? Ans: Classifications of switching systems are givenin block diagram belo