Question

A piece of platinum wire has resistance of 2.5 ohm at 0 degree Celsius if its temperature coefficient of resistance is 4×10^-3 upon degree Celsius find the resistance of the wire at 80 degrees celsius​

Answer 1

Given info : A piece of platinum wire has resistance of 2.5 ohm at 0°C . its temperature coefficient of resistance is 4 × 10¯³/°C

To find : The resistance of the wire at 80°C is...

solution : using formula, R = R₀[1 + α∆T ]

where R₀ is initial resistance, α is coefficient of resistance and ∆T is change in temperature.

here R₀ = 2.5 ohm

α = 4 × 10¯³/°C

and ∆T = 80°C - 0°C = 80°C

now R = 2.5 [1 + 4 × 10¯³ × 80]

= 2.5 [1 + 0.320 ]

= 2.5 × 1.32

= 3.3 ohm

Therefore the resistance of the wire at 80°C is 3.3 ohm.