Question

Assertion :In the formula $P=\frac{2}{3}$ E, the term E represents translational kinetic energy per unit volume of gas. Reason: In case of monoatomic gas translational kinetic energy and total kinetic energy are equal.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Translational Kinetic energy of a gas=$TKE=\frac{3}{2}nkT$$=\frac{3}{2}PV$

$⟹$ Translational Kinetic Energy per unit volume $=E=\frac{TKE}{V}=\frac{3}{2}P$

$⟹P=\frac{2}{3}E$

For monoatomic gas, there is no rotational degree of freedom, thus the kinetic energy is purely translational.