AP EAMCET201920 Apr 2019Morning ShiftPhysicsThermodynamicsActual
A gas expands with temperature according to the relation, (V=k T^ 2 / 3 ), where (k ) is a constant. Work done when the temperature changes by (60 ~K ) is ( (R= ) universal gas constant.)
Options
- A(10 R )
- B(20 R )
- C(50 R )
- D(40 R )
Correct answer
D. (40 R )
Step-by-step solution
Given, (V=k T^ 2 / 3 ) From definition of work done, ( aligned d W & =P d V= R T V d V & = R T k T^ 2 / 3 d V (i) aligned ) Now, (V=k T^ 2 / 3 ) Taking derivative on the both sides, we get (d V=K 2 3 T^ -1 / 3 d T (ii) ) Substituting the value of Eqs. (ii) in Eqs. (i) and taking integration on the both sides, we get ( aligned W & = 2 3 R _ T₁ ^ T₂ d T= 2 3 R (T₂-T₁ ) & = 2 3 R(60-0)= 2 3 R 60=40 R aligned )