NEET-XII-Physics
P1 year:2019
- #14A copper rod of 88 cm and an aluminium rod of
unknown length have their increase
in length independent of increase in
temperature. The length of aluminium rod is :
(``Α_{Cu}
= 1.7 × 10^{-5} K^{-1}`` and ``α_{
Al}= 2.2 × 10^{-5} K^{-1}``)
(1) 6.8 cm
(2) 113.9 cm
(3) 88 cm
(4) 68 cmdigAnsr: 4Ans : ( 4 )
Sol. ``α_{cu} L_{cu}= α_{AL} L_{AL}``
``1.7 × 10^{-5} × 88 cm = 2.2 × 10^{-5} × L_{AL}``
``L_ {AL}``=``\frac {1.7 X 88}{2.2}``
=68 cm