NEET2008PhysicsMechanical Properties of SolidsActual
If a wire is extended to a new length (l ), the work done is
Options
- A( Y A l (l-l^ ) )
- B( Y A l (l-l^ )^2 )
- C( 1 2 Y A l (l-l^ )^2 )
- D(2 Y A l (l-l^ )^2 ).
Correct answer
C. ( 1 2 Y A l (l-l^ )^2 )
Step-by-step solution
Y= F / A l l F= Y A l l=k l Force extension If the extension is x , work done in extending by d x F= Y A l l=k l If x is (l^ -l ), W= 1 2 k (l^ -l )^2 i.e. work done is 1 2 Y A l (l-l^ )^2 .