Question

2 straight metallic strips each of thickness t & length l are riveted together . their coeeficients of linear expansion are a & a . if they are heated through a temp (delta t) , the bimetallic strip will bend to form an arc of what radius??

Answer 1

Answer:

let Δl be the difference between final lengths of two strips and Δr=t be the difference in their radii.

Then, since l=rθ

Hence, Δl=θΔr since θ is same for both arcs.

We know that l

′

=l(1+αΔT)

Therefore, θ=

r

l

=

t

l(α

2

−α

1

)ΔT

r=

(α

2

−α

1

)ΔT

t