MCQ
We sit in the room with windows open. Then,
  • A
    air pressure on the floor of the room equals the atmospheric pressure but the air pressure on the ceiling is negligible
  • air pressure is nearly the same on the floor, the walls and the ceiling
  • C
    air pressure on the floor equals the weight of the air column inside the room (from floor to ceiling) per unit area
  • D
    air pressure on the walls is zero, since the weight of air acts downward

Answer

Correct option: B.
air pressure is nearly the same on the floor, the walls and the ceiling
b
(b)

Gas molecules move randomly and effect of gravity on them is insignificantly low. So, pressure exerted by gas molecules is same everywhere.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The maximum possible velocity of a satellite orbiting round the earth in a stable orbit is
A screw gauge gives the following readings when used to measure the diameter of a wire

Main scale reading : $0 \,\mathrm{~mm}$

Circular scale reading $: 52$ $divisions$

Given that $1\, \mathrm{~mm}$ on main scale corresponds to $100\, divisions$ on the circular scale. The diameter of the wire from the above data is ...... $cm$

Ametal wire is clamped between two vertical walls.At $20 ^o C$ the unstrained length of the wire is exactly equal to the separation between walls. If the temperature of the wire is decreased the graph between elastic energy density $(u)$ and temperature $(T)$ of the wire is
A projectile is fired at $30^{\circ}$ to the horizontal, The vertical component of its velocity is $80 \;ms ^{-1}$, Its time flight is $T$. What will be the velocity of projectile at $t =\frac{ T }{2}$?
A ball of mass ${m_1}$ and another ball of mass ${m_2}$ are dropped from equal height. If time taken by the balls are ${t_1}$ and ${t_2}$ respectively, then
As shown in the figure, a block of mass $\sqrt{3}\, kg$ is kept on a horizontal rough surface of coefficient of friction $\frac{1}{3 \sqrt{3}}$. The critical force to be applied on the vertical surface as shown at an angle $60^{\circ}$ with horizontal such that it does not move, will be $3 x$. The value of $3x$ will be

$\left[ g =10 m / s ^{2} ; \sin 60^{\circ}=\frac{\sqrt{3}}{2} ; \cos 60^{\circ}=\frac{1}{2}\right]$

In the given circuit switch $S$ is closed at $t = 0$ . The current $I$ in the figure at time $t$ is
If a shell fired from a cannon, explodes in mid air, then
The potential energy of a particle varies with distance $x$ from a fixed origin as $U\, = \,\frac{{A\sqrt x }}{{{x^2} + B}}$ Where $A$ and $B$ are dimensional constants then find the dimensional formula for $A/B$
$A$ horizontal force $F = mg/3$ is applied on the upper surface of a uniform cube of mass $‘m’$ and side $‘a’$ which is resting on a rough horizontal surface having $\mu_S = 1/2$. The distance between lines of action of $‘mg’$ and normal reaction $‘N’$ is :