Steel wire of length 'L' at 40^(@)C is suspended from the ceiling and then a mass 'm' is hung from its free end. The wire is cooled dowa from 40^(@)C" to "30^(@)C to regain its original length 'L'. The coefficient of linear thermal expansiou of the steel is 10^(-5)//^(@)C, Young's modulus of steel is 10^(11)N//m^(2) and radius of the wire is 1 mm. Assume that L gt gt diameter of the wire. Then the value of 'm' in kg is nearly

Steel wire of length 'L' at 40^(@)C is suspended from the ceiling and

1.	Steel wire of length 'L' at 40^(@)C is suspended from the ceiling and then a mass 'm' is hung from its free end. The wire is cooled dowa from 40^(@)C" to "30^(@)C to regain its original length 'L'. The coefficient of linear thermal expansiou of the steel is 10^(-5)//^(@)C, Young's modulus of steel is 10^(11)N//m^(2) and radius of the wire is 1 mm. Assume that L gt gt diameter of the wire. Then the value of 'm' in kg is nearly
Answer» 1 2 3 4 Solution :Change in LENGTH `DELTA L =(MGL)/(YA) = L alpha Delta T therefore m~~3 kg`. CORRECT choice : (c ).

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