To solve this problem we will apply the concepts related to resistance as a function of temperature, product of the relationship between the squared voltage and the power. Mathematically this is,
[tex]R = \frac{v^2}{P}[/tex]
Here,
R = Resistance (At function of temperature)
v = Voltage
P = Power
Then we have,
R at 140°C (7 times room temperature),
[tex]R(140\°C) = \frac{125^2}{7.5}[/tex]
[tex]R(140\°C) = 2083.33\Omega[/tex]
The relationship between normal temperature and increased temperature would then be given by,
[tex]R(140\°C) = R(20\°C)(1 +\alpha (\Delta T))[/tex]
[tex]R(140\°C) = R(20\°C)(1+(4.5*10^{-3})(140-20))[/tex]
[tex]R(20\°C) = \frac{2083.33}{1.54}[/tex]
[tex]R(20\°C) = 1352.81\Omega[/tex]
Therefore the correct value of the group of answer is 1350
