Answer:
The temperature of the filament when the flashlight is on is 2020 °C.
Explanation:
The resistivity varies linearly with temperature:
[tex] R = R_{0}[1 + \alpha*(T-T_{0})] [/tex] (1)
Where:
T: is the temperature of the filament when the flashlight is on=?
T₀: is the initial temperature = 20 °C
α: is the temperature coefficient of resistance = 0.0045 °C⁻¹
R₀: is the resistance at T₀ = 1.5 Ω
When V = 3.0 V, R is:
[tex]R = \frac{V}{I} = \frac{3.0 V}{0.20 A} = 15 \Omega[/tex]
By solving equation (1) for T we have:
[tex]T = \frac{R-R_{0}}{\alpha*R_{0}} + T_{0} = \frac{15-1.5}{0.0045*1.5} + 20 = 2020 ^{\circ} C[/tex]
Therefore, the temperature of the filament when the flashlight is on is 2020 °C.
I hope it helps you!
