Thermal Equilibrium

Diagram shows a horizontal cylindrical container of length $30 \mathrm{cm}$, which is partitioned by a tight-fitting separator. The separator is diathermic but conducts heat very slowly. Initially the separator is in the state shown in the diagram. The temperature of left part of cylinder is $100 \mathrm{K}$ and that on right part is $400 \mathrm{K}$. Initially the separator is in equilibrium. As heat is conducted from right to left part, separator displaces to the right. Find the displacement of separator after a long when gases on the two parts of cylinder are in thermal equilibrium.

 Which of the following is constant in a diathermic boundary?
 

What is diathermic boundary?

A diathermic boundary is a boundary that allows_____to transfer. 

 Which of the following is constant in a diathermic boundary?
 

A diathermic boundary is a boundary that allows heat to transfer.

Define adiabatic boundary?

All such boundaries of thermodynamic system that are impermeable to the flow of heat across itself are called _____.

Which one of the following is correct about an adiabatic boundary?

Adiabatic refers to a process in which no heat is transferred into or out of a system.

When the temperature of a body is equal to that of the surroundings then the body appears
 

Zeroth law of thermodynamics 

An adiabatic wall is one which

A diathermic wall is one which

When the temperature of a body is equal to that of the surroundings then the body appears
 

Zeroth law of thermodynamics 

At the thermal equilibrium state temperature is constant.

Ice at $0^{o}C$ is added to $200 gm$ of water initially at ${70}^{o}C$ in a vacuum flask. When $50 gm$ of ice has been added and has all melted, the temperature of flask and contents is ${40}^{o}C$, When a further $80 gm$ of ice is added and has all melted, the temperature of the whole becomes ${10}^{o}C$. Neglecting heat lost to surroundings the latent heat of fusion of ice is :

Cotyledons are also called-

The thermo emf E (in volts) of a certain thermocouple is found to vary with Q (in C) according to equation $\left(E=20Q-\frac{Q^2}{20},\right)\text{where} Q$ is temperature of the hot function, the cold function being kept at $0^{o}C$ . Then, the neutral temperature of the thermocouple is