Question

4. The resistance of a nichrome wire at
20°C is 102. Ifits temperature coefficient
of resistivity of nichrom is 0.004/°C, find
the resistance of the wire at boiling point​

Answer 1

Answer:

use the equation Rf = R.(1+alpha∆T)

Explanation:

Rf = 102{1+0.004(100)}

I I think now u can solve the equation

Answer 2

Answer: 142.8 ohm

Concept: we have the equation

Rt = R0(1+alpha∆T)

where,

Rt = Resistance at temperature t

R0 = Resistance of wire at room temperature

alpha =  temperature coefficient of resistivity

∆T = temperature at which you have to find resistance

Given: Resistance of a nichrome wire at 20°C is 102 ohm

Temperature coefficient of resistivity of nichrome is 0.004/°C

To find: The resistance of the wire at boiling point​

Explanation:

Boiling point of water is 100°C

∆T = 100°C

Room temperature  = 20°C

Hence R0 = 102 ohm

we have the equation

Rt = R0(1+alpha∆T)

where,

Rt = Resistance at temperature t

R0 = Resistance of wire at room temperature

alpha =  temperature coefficient of resistivity

∆T = temperature at which you have to find resistance

putting values in the equation

Rt = R0(1+alpha∆T)

Rt = 102(1+ 0.004*100)

Rt = 102(1+0.4)

Rt = 102(1.4)

Rt = 142.8 ohm

The resistance of the wire at boiling point​ is 142.8 ohm

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