InterviewSolution
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InterviewSolution
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Two mole of an ideal monatomic gas are confined within a cylinder by a mass less spring loaded with a frictionless piston of negligible mass and crossectional area `4xx10^(-3)m^(2)`. The gas is heated by a heater for some time. During this time the gas expands and does `50J` of work in moving the piston through a distance of `0.01`m. The temperature of gas increases by `50`k. Change in internal energy of the gas isA. `1246.5 J`B. `124.65 J`C. `200 J`D. `12.46 J` |
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Answer» Correct Answer - A When the gas is heated it expands `&` pushes the piston by x. If k is force constanat of spring and `A` is area of crossection of the piston. It `P_(0)` is atmospheric pressure then at equilibrium of piston the pressure of the gas on the piston `P=P_(0)+(kx)/(A)` The increas in the volume of the gas by samll movement of x of piston is `dv=Adx` `W=int_(0)^(X)Pdv=P_(0)Ax+(1)/(2)kx^(2)` Putting `A=4xx10^(-3)m^(2),x=0.1m, W=50 J`. `P_(0)=1.013xx10^(5) Nm^(-2)` in above equation `:. k=1896 Nm^(-1)` |
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