Question
Why rooms are provided with the ventilators near the roof?
✓
Answer
It is done so to remove the harmful impure air and to replace it by the cool fresh air. The air we breath out is warm and so it is lighter. It rises upwards and can go out through the ventilator provided near the roof. The cold fresh air from outside enters the room through the doors and windows. Thus, the convection current is set up in the air.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A glass flask of volume $250 \mathrm{~cm}^3$ is just filled with mercury at $20^{\circ} \mathrm{C}$. How much mercury overflows when the temperature of the system is raised to $100^{\circ} \mathrm{C}$ ? The coefficient of volume expansion of glass is $12 \times 10^{-6}\left({ }^{\circ} \mathrm{C}\right)^{-1}$ and that of mercury is $18 \times 10^{-5}\left({ }^{\circ} \mathrm{C}\right)^{-1}$.
→Moon is seen to be of $\Big(\frac{1}{2}\Big)^\circ$ diameter from the earth. What must be the relative size compared to the earth?
→State the rules for finding the number of significant figures in a measurement.
The displacement of an object changes with time according to $s=t^3-6 t^2+3 t+4$, then the acceleration of the object at instant is zero. What is its velocity?
→Determine $\lambda$ such that: $\vec{\text{A}}=2\hat{\text{i}}+\lambda\hat{\text{j}}+\hat{\text{k}};\ \vec{\text{B}}=4\hat{\text{i}}-2\hat{\text{j}}-2\hat{\text{k}}$ are perpendicular to each other.
→Answer the following: A screw gauge has a pitch of 1.0mm and 200 divisions on the circular scale. Do you think it is possible to increase the accuracy of the screw gauge arbitrarily by increasing the number of divisions on the circular scale ?
Water flows through a horizontal tube as shown in If the difference of heights of water column in the vertical tubes is 2cm, and the areas of cross-section at A and B are $4cm^2$ and $2cm^2$ respectively, find the rate of flow of water across any section.
→If two waves of the same frequency but of different amplitudes travelling in opposite directions through a medium superpose upon each other, will they form stationary wave? Is energy transferred? Are there any nodes?
Shows plot of $\frac{\text{PV}}{\text{T}}$ versus P for $1.00 \times 10^{-3} \mathrm{~kg}$ of oxygen gas at two different temperatures. What does the dotted plot signify?
→Draw displacement-time graph for a uniformly accelerated motion. What is its shape?