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Surface Tension — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsSurface Tension1 Mark
Question
Assertion : When a gas is allowed to expand, work done by gas is positive.
Reason : Force due to gaseous pressure and displacement (of piston) are in the same direction.
✓

Answer

(a) Since the gaseous pressure and the displacement(ofpiston)areinthesamedirection.Therefore$\theta=0^{\circ}$$\therefore$ Work done $=F_s \cos \theta=F_s=$ PositiveThus during expansion work done by gas is positive.

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