MCQ
When vapour condenses into liquid
- AIt absorbs heat
- ✓It liberates heat
- CIts temperature increases
- DIts temperature decreases
✓
Answer
Correct option: B.
It liberates heat
(b) In vapor to liquid phase transition, heat liberates.
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
In a resonance pipe the first and second resonances are obtained at depths $22.7 \mathrm{~cm}$ and $70.2 \mathrm{~cm}$ respectively. What will be the end correction
→Material $A$ has critical angle $i_A$, and material $B$ has critical angle $i_B\left(i_B>i_A\right)$. Then which of the following is true
(i) Light can be totally internally reflected when it passes from $B$ to $A$
(ii) Light can be totally internally reflected when it passes from $A$ to $B$
(iii) Critical angle for total internal reflection is $i_B-i_A$
(iv) Critical angle between $A$ and $B$ is $\sin ^{-1}\left(\frac{\sin i_A}{\sin i_B}\right)$
→(i) Light can be totally internally reflected when it passes from $B$ to $A$
(ii) Light can be totally internally reflected when it passes from $A$ to $B$
(iii) Critical angle for total internal reflection is $i_B-i_A$
(iv) Critical angle between $A$ and $B$ is $\sin ^{-1}\left(\frac{\sin i_A}{\sin i_B}\right)$
Two bodies having same mass $40 \mathrm{~kg}$ are moving in opposite directions, one with a velocity of $10 \mathrm{~m} / \mathrm{s}$ and the other with $7 \mathrm{~m} / \mathrm{s}$. If they collide and move as one body, the velocity of the combination is
→A uniform chain of length $L$ and mass $M$ is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If $g$ is acceleration due to gravity, the work required to pull the hanging part on to the table is
→Three liquids of densities $d, 2 d$ and $3 d$ are mixed in equal proportions of weights. The relative density of the mixture is
→Two mutually perpendicular simple harmonic vibrations have same amplitude, frequency and phase. When they superimpose, the resultant form of vibration will be
The elasticity of invar
A conductor lies along the $z-$axis $a$ $-1.5$$ \le Z < 1.5\,m$ carries a fixed current of $10.0\ A$ in $ - {\hat a_z}$ direction (see figure). For a field $\vec B$ $=$ $3.0 \times 10^{-4}$ $e^{-0.2x}$ ${\hat a_y}\,T$ find the power required to move the conductor at constant speed to $x = 2.0\ m, y = 0\ m$ in $5 \times 10^{-3}\ s$. Assume parallel motion along the $x-$axis........$ W$
→The type of waves that can be propagated through solid is
Which one is correct relation for thermionic emission