Question

A brass rod at 30°c is observed to be 1 m long when measured by a steel scale which is correct at 0°c . Find the corrected length of the rod at 0°c .Given a for steel is 1.2×10^-5°c-1 & a for brass is 1.9 × 10^-5°c-1​

Answer 1

Let the length of tube and scale at 0

o

C be l. Then,

Change in measured tube length

Δl=Thermal expansion of brass− Thermal expansion of steel

Δl=lα

B

ΔT−lΔα

B

ΔT

Δl=lΔT(αB−αS)

Δl=l(40−0)(19×10

−6

−11×10

−6

)

So, new length measured by scale=l+Δl

⇒5=l+l(40)(7×10

−6

)

⇒

1+40×7×10

−6

5

=l

⇒l=4.9986≈4.999m

Answer 2

Answer:

the answer of the following question is

I =4.9986≈ 4.999m

Explanation: