In Thevenin’s theorem Vth is __________
a) Sum of two voltage sources
b) A single voltage source
c) Infinite voltage sources
d) 0

Explanation

The middle walll is weakly conducting.
Thus, after a long time the temperature of
both the parts will be equal . The final
position of the separating wall be at a
distance x from the left end. So it is at a
distance (30-x) from right end.
Putting combined gas equation of one side
of the separating wall
` ((P_1)xx (V_1)/ T_1) = ((P_2) xx (V_2)/ T_2)`
` rArr (P xx 20A / 400) = ( P' xx xA / T) ` ...........(i) `
` rArr (P xx (10A) / 100) = (P' xx ( 30A - x ) A / T)` ..........(ii)
using (i) and (ii)
` ( P xx 20A xx 100 / 400 xx P xx 10A) = (P' xx xA / TP' (30- x) A) `
` rArr (1/2 = (x/ 30-x))`
` rArr 30-x = 2 x `
` rArr 30= 3x `
` rArr x = 10 cm `
The separator will be at a distance 10 cm
from the left end.