AP EAMCET202018 Sep 2020Evening ShiftPhysicsMechanical Properties of SolidsActual
A force (F ) is needed to break a copper wire having radius (R ). The force needed to break a copper wire of radius (2 R ) will be
Options
- A( F 2 )
- B(2 F )
- C(4 F )
- D( F 4 )
Correct answer
C. (4 F )
Step-by-step solution
Force needed to break a wire is directly proportional to its cross-sectional area. ( array rlr i.e. F & A F₂ F₁ & = A₂ A₁ = R₂^2 R₁^2 & = ( R₂ R₁ )^2= ( 2 R R )^2 & [ R₁=R, R₂=2 R ] & =4 F₂ & =4 F₁=4 F [ F₁=F ] array )