Thermal Properties of Matter - Result Question 1

1. A copper rod of 88cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is : (αCu=1.7×105K1. and αA1=2.2×105K1 )

[2019]

(a) 6.8cm

(b) 113.9cm

(c) 88cm

(d) 68cm

Show Answer

Solution:

  1. (d) lCu=lCu(1+αCuΔT)

ΔlCu=lCuαCuΔT

lAl=lAl(1+αAlΔT)

ΔlAl=lAlαAlΔT

Since, change in length is independent of temperature

αCulCu=αAllAl

1.7×105×88cm=2.2×105×1Al

lAl=1.7×882.2=68cm



NCERT Chapter Video Solution

Dual Pane