When a bar of iron 50.0 cm long at15 ⁰C is heated in a furnace, it becomes 50.4 cm. If the coefficient of linear expansion of iron is 0.000011⁰C^-1,find the temperature of the furnace.

Given: α= 0.000011⁰C^-1

L_o= 50cm

L_t=50.4 cm

T₁=15^oC

α= L_t-L_o/L_ox ΔT

here, Lt is the length of the rod when the temperature is "increased" to "T"
Lo is the initial tlength.

" ΔT " is the difference between the two temperature.i.e. final temp-intial temp

so write the formula as:


α= L_t-L_o/L_o* (T₂ - T₁)

where initial temp. is T₁ and final temp is T₂.

Put all the values in the above formula and solving it you will get,

T₂= 742.3^oC