(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A motor winding has a risitance of 80 ohm at room temperature of 20c before

switching on to a 230v. after 4 hour run wionfing resistance is 100 ohm

find the temperature rise if the matrial resistance temperature co-efficient is 1/234.5/c.

R at 20 = 80 ohm

R at t = 100 ohm

alpha =1/234.5

2. Relevant equations

R at 20/R at t = R at 0c (1 - at)/ R at 0c (1-at)

3. The attempt at a solution

80/100 = 1+0.004264X20/1+0.004264t

t = 83.630 c

Rise is t-20 = 83.630-20

t rise is 63.63 c

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# Homework Help: Finding resistance and temp co-efficient

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