The temperature coefficient of resistance for two material A and B are `0.0031^(@)C` and `0.0068^(@)C^(-1)` respectively .Two resistance `R_(1) and R_(2)` made from material A and B respectively . Have resistance of `200 Omega` and `100 Omega` at `0^(@)C`. Show as a diagram the colour cube of a carbon resistance that would have a resistance equal to the series combination of `r_(1) and R_(2)` at a temperature of `100^(@)C` (Neglect the ring corresponding to the tolerance of the carbon resistor)

Answer

yellow , orange ,black

Explanation

As` 100^(@)C` for meterial A,
`R'_(1) = R_(1)[1+alpha_(1) (100 - 0)]`
`=200[1 + 0.0031 xx100]`
`= 200 xx 1.31 = 262 Omega`
At `100^(@)C` for meterial B
`R'_(2) = R_(2) [1+alpha_(2) (100 - 0)]`
`= 100 [1+ 0.0068 xx 100]`
`= 100 xx 1.68 = 168 Omega`
Effective resistance in series conbination of resistance
`R = R_(1) + R'_(2) = 262 + 168 = 430 Omega`
The number atteched `4,3,0` are yellow, orange and brown
. The given corbon resistor is