Part A Review | Constants The filament of a lightbulb has a resistance of R0 = 12 at 20 °C and 140 when hot. Calculate the temperature of the filament when it is hot, and take into account the change in length and area of the filament due to thermal expansion (assume tungsten for which the thermal expansion coefficient is ≈ 5.5 × 10-6 (C°) -¹). Use the equation pà = Po (1+ a(T – To)), assuming an average temperature coefficient of resistivity a = 0.0045 (C°)-1. Express your answer using two significant figures. T = V ΑΣΦ Submit Request Answer Part B °C In this temperature range, what is the percentage change in resistance due to thermal expansion? Express your answer using two significant figures. ΕΠΙ ΑΣΦ Rexpansion-Ro Ro Submit Request Answer Part C ? What is the percentage change in resistance due solely to the change in p? Express your answer using two significant figures. ΑΣΦ Rchange in p Ro Ro Submit Request Answer ?