Explain it with reasons plz

Asked by vishakhachandan026 | 1st Apr, 2019, 08:31: AM

Expert Answer:

let us assume the thickness of carbon part is l1 and as that off for brass is l2
G i v e n space c o e f f i c i e n t space o f space l i n e a r space e x p a n s o n space a n d space r e s i s t i v i t y space f o r space c a r b o n space i s space alpha subscript c space end subscript a n d space rho subscript c space end subscript a n d space a s space t h a t space o f space b r a s s space i s space alpha subscript b space end subscript a n d space rho subscript b space end subscript r e s p e c t i v e l y
t h e space r e s i s t i v i t y space o f space a n y space m a t e r i a l space v a r r y space w i t h space t e m p e r t u r e space a s space rho space equals rho subscript 0 space space end subscript open square brackets 1 plus alpha increment T close square brackets
a n d space i t s space i s space g i v e n space i n i t a l space r e s i s tan c e space i s space e q u a l space t o space f i n a l space r e s i s tan c e
r e s i s tan c e space i s space g i v e n space a s space R space equals fraction numerator rho cross times l over denominator A end fraction space w h e r e space A space i s space a r e a space o f space c r o s s space s e c t i o n space a n d space i n space t h i s space q u e s t i o n space i t space r e m a i n space s a m e

s o space R subscript i space end subscript equals R subscript f space end subscript
fraction numerator rho subscript c space end subscript cross times l subscript 1 over denominator A end fraction plus fraction numerator rho subscript b space end subscript cross times l subscript 2 over denominator A end fraction space equals fraction numerator rho subscript c space end subscript open square brackets 1 minus alpha subscript c space end subscript cross times increment T close square brackets cross times l subscript 1 space space space end subscript space over denominator A end fraction space plus fraction numerator rho subscript b space end subscript open square brackets 1 minus alpha subscript b space end subscript cross times increment T close square brackets cross times l subscript 2 space space space end subscript space over denominator A end fraction
s o l v i n g space t h i s space e q u a t i o n space w e space g e t
l subscript 1 over l subscript 2 space equals space fraction numerator alpha subscript b space end subscript cross times rho subscript b space end subscript over denominator alpha subscript c cross times rho subscript c space end subscript end fraction

Answered by Ankit K | 3rd Apr, 2019, 11:44: PM