The figure shows a glass tube (linear coefficient of expansion is $\alpha$) completely filled with a liquid of volume expansion coefficient $\gamma$. On heating,the length of the liquid column does not change. Choose the correct relation between $\gamma$ and $\alpha$.

Out of the following,in which vessel will the temperature of the solution be higher after the salt is completely dissolved?

Give one example each for solid,liquid,and gas showing expansion with an increase in temperature and contraction with a decrease in temperature.

One $kg$ of water, at $20, ^oC$, is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of $20, \Omega$. The rms voltage in the mains is $200, V$. Ignoring heat loss from the kettle, the time taken for water to evaporate fully is close to.......... $min$. [Specific heat of water $= 4200, J/kg, ^oC$, Latent heat of water $= 2260, kJ/kg$]

The surface of the lake is at $2^{\circ} C$. The temperature of the bottom of the lake is ....... $^{\circ} C$.

An earthen pitcher used in summer cools water in it essentially by evaporation of water from its porous surface. If a pitcher carries $4 \,kg$ of water and the rate of evaporation is $20 \,g$ per hour,the temperature of water in it decreases by $\Delta T$ in two hours. The value of $\Delta T$ is close to ........... $^{\circ} C$ (ratio of latent heat of evaporation to specific heat of water is $540^{\circ} C$).