A Student records the initial length l, change in temperature DeltaT and change in length Deltal of a rod as follows : If the first observation is correct what can you say about observations 2, 3 and 4.

A Student records the initial length l, change in temperature DeltaT a

1.	A Student records the initial length l, change in temperature DeltaT and change in length Deltal of a rod as follows : If the first observation is correct what can you say about observations 2, 3 and 4.
Answer» Solution :From FIRST observation, `alpha=(Deltal)/(lDeltaT)` `=(4xx10^(-4))/(2xx10)` `=2xx10^(-5)" "^(@)C^(-1)` From second observation, `Deltal=alphalDeltaT` `:.Deltal=2xx10^(-5)xx1xx10` `=2xx10^(-4)m!=4xx10^(-4)m` `:.` Thus, the observation is incorrect From third observation, `Deltal=alphalDeltaT` `=2xx10^(-5)xx2xx20` `=8xx10^(-4)m!=2xx10^(-4)m` `:.` Thus, the observation is incorrect. From fourth observation, `Deltal=alphalDeltaT` `=2xx10^(-5)xx3xx10` `=6XX10^(-4)m=6xx10^(-4)m` Thus, the observation is true.