Question 3 :
The process by which wet clothes dry up is called _____________.

Question 6 :
Assertion: It takes longer to dry wet clothes in humid weather. Reason: The presence of humidity in the atmosphere that means water vapour in the atmosphere is already heavy so when we try to dry clothes the evaporation process is slow but effective due to the presence of water vapour in the air.

Question 7 :
Assertion: A desert cooler cools better on a hot dry day. Reason: On a hot dry day, the temperature is high and humidity is low. The water takes heat from the hot desert cooler and evaporates. The evaporation of water cools the pads and the circulating water.

Question 10 :
Drinking of hot tea from a saucer preferred to a cup, because:

Question 11 :
While putting clothes for drying up, why dowe spread them out?

Question 12 :
Assertion: We wear cotton clothes in summer. Reason: The mechanism of our body to keep us cool, during evapourisation the particles at the surface of the liquid gain energy from the surroundings or body surface and change into vapour. The heat energy equal to the latent heat of vapourisation is absorbed from the body leaving the body cool.

Question 13 :
Assertion: Our palm feels cold when we put petrol on it. Reason: During evaporation, particles of the liquid absorb energy from the surrounding or the surface of the palm to compensate for the loss of energy, making the surroundings cool.

Question 14 :
Which one of the following factors do not affect the rate of evaporation?

Question 15 :
Rinku and Pinku had half day schools during summer. They used to go to school by auto. Observed that the auto driver covered the top of the auto by some mats which keeps the auto cool. Which of the following phenomenon is involved here?

Question 16 :
Assertion: In a container containing gas A at temperature $ 400\,K $ , some more gas A at temperature $ 400\,K $ is introduced. The pressure of the system increases. Reason: Increase in gaseous particles increases the number of collisions among the molecules , hence the pressure increases .

Question 18 :
What is the pressure of gas in the cylinder after $1$ h?

Question 19 :
Two identical containers, each of volume $V_o$, are joined by a small pipe of negligible volume. The containers contain identical gases at temperature $T_o$ and pressure $P_o$. One container is heated to temperature $2T_o$ while maintaining the other at the same temperature, $T_o$. The common pressure of the gas is P and n is the number of moles of gas in container at temperature $2T_o$, then?

Question 20 :
Assertion: Gases become denser at high pressure. Reason: At high pressures, gases deviate from Boyle's law.

Question 21 :
Under what pressure will carbon dioxide have the density of $2.2$ g/litre at $300$K? For $CO_2$, $a=3.6$ atm $l^2 mol^{-2}$ and $b=0.05$ $l-mol^{-1}$.

Question 22 :
The pressure exerted on walls of a $3$L flask when $7$g of $N_2$ is introduced into it at $300$K should be?(assume ideal behaviour of gas)

Question 23 :
An amount of $1$ mole of a gas is changed from its initial state($20$L, $2$ atm) to final state($4$L, $10$ atm), respectively. If the change can be represented by a straight line in P-V curve, the maximum temperature achieved by the gas in the process is?($R=0.08$L-atm/K-mol)

Question 25 :
Burns caused by steam are more severe that burns caused by boiling water.