A thin brass sheet at 10∘C and thin steel sheet at 20∘C have the same surface area.The common temperature at which both would have the same area : (Coefficient of linear expansion for brass and steel are respectively 19×10−6/∘C and 11×10−6/∘C.)
A
−3.75∘C
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
−2.75∘C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2.75∘C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
3.75∘C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is D−3.75∘C αb=19×10−6/∘ C So, βb=38×10−6/∘C αS=11×10−6/∘C So, βS=22×10−6/∘C Now, we know, A2=A1(1+βdt), where dt = change in temperature Let the common temperature at which the plates will have same area be t, Then, Ab=A0(1+βb(t−10)) and AS=A0(1+βS(t−20)) βb(t−10)=βs(t−20) solving we get, t=−3.75oC