(13%) Problem 6: A resistor made of Nichrome wire is used in an application wher
ID: 1642284 • Letter: #
Question
(13%) Problem 6: A resistor made of Nichrome wire is used in an application where its resistance must not change by more than 1.00% from its value at 20°C Material Coefficient Material Coefficient Conductors Silver Copper Gold Aluminum Tungsten Iron Platinum Conductors Nichrome Manganin Constantan 0.002 x 10 Semiconductors Carbon Germanium 50x 1 Silicon -3 3.8 x 10 3.9 x 10 3.4 x 10 3.9 x 10 4.5 x 10 5.0 x 10 .93 x 10S 0.4 x 10 0.000 x 10 0.5x 10 50 x 10 -70 x 10 ©theexpertta.com > 50% Part (a) what is the minimum temperature, in degrees Celsius, at which the resistor can be used?Explanation / Answer
relation between resistance and temperature is given by:
R = R0*(1 + alpha*dT)
R - R0 = R0*alpha*dT
max change in resistance allowed is 1%
R - R0 = 0.01*R0
Using this
0.01*R0 = R0*alpha*dT
dT = 0.01/alpha
alpha for nichrome = 0.4*10^-3
dT = 0.01/(0.4*10^-3) = 25 C
Minimum temperature can be
dT = |T - T0| = 25
T0 = 20
T - 20 = -25
T = -5 C (your answer)
max temperature can be
T = 45 C
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.