Physics

Thermal Properties of Matter

274 Questions

Thermal properties of matter examine how substances react to heat, covering concepts like temperature, specific heat, and phase changes. This topic is regularly tested in the physics and general science sections of competitive exams. Use this collection to solve numericals on heat transfer, thermal equilibrium, and melting points.

Heat transfer and mixingMelting and freezing pointsThermal expansion and densityTriple point of waterCarnot cycle applications

Thermal Properties of Matter Questions

Multiple choice physics the kinetic model of matter force and kinetic theory change of states phase change

Water in a lake is changing into ice at $0^{o}C$. When the atmospheric temperature is $10^{o}C$. If the time taken for $1\ cm$ thick ice layer to be formed is $7$ hour, the time required for the thickness of ice to increase from $1\ cm $ to $2\ cm$ is

  1. $7\ hour$
  2. $14\ hour$
  3. $<7\ hour$
  4. $>14\ hour$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The rate of ice formation is proportional to the thickness already formed because the heat must conduct through the existing ice layer. If it takes 7 hours to form the first 1 cm, the next 1 cm (from 1 cm to 2 cm) takes three times the duration of the first interval in some models, but standard physics problems of this type often follow the t proportional to x^2 rule. Specifically, t1 = k(x1^2), t2 = k(x2^2 - x1^2). Here, 7 = k(1^2), so k = 7. The time for the next cm is 7(2^2 - 1^2) = 7(3) = 21 hours. Given the options, 14 hours is often cited in simplified textbooks, but mathematically it should be 21.

Multiple choice physics the kinetic model of matter force and kinetic theory change of states phase change

How much heat energy is gained when 5 kg of water at  $20 ^ { \circ } \mathrm { C }$ is brought to its boiling point?

  1. 1680 KJ

  2. 1700 KJ

  3. 1720 KJ

  4. 1740 KJ
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$Q = mc\Delta \theta $

$ = 5 \times \left( {1000 \times 4.2} \right) \times \left( {100 - 20} \right)$
$ = 1680 \times {10^3}J$
$ = 1680\,KJ$
Hence,
option $(A)$ is correct answer.

Multiple choice physics the kinetic model of matter force and kinetic theory change of states phase change

When $1\;g$ of water at $100^{\circ}C$ gets converted into steam at the same temperature, the change in volume is approximately :

  1. $1\;cc$
  2. $1000\;cc$
  3. $1500\;cc$
  4. $1670\;cc$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given: When 1g of water at $100^∘C$ gets converted into steam at the same temperature, 

To find the change in volume
Solution:
We know, 
Density of water, $\rho=1000kg/m^3=1 g/cm^3$
Density of steam, $\rho=0.6kg/m^3=0.0006 g/cm^3$
Mass of the water and mass of water, $m=1g$
Volume of water is
$m=\rho V\\implies V=\dfrac m\rho=\dfrac 11\\implies V=1cc$
Volume of steam, 
$V'=\dfrac m\rho=\dfrac 1{0.0006}=1666.7cc\approx1667cc$
The change in volume, 
$\Delta V=V'-V\\implies \Delta V=1667-1=1666cc$

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

The freezing point of pure water is ____________.

  1. 100 degree centigrade

  2. 50 degree centigrade

  3. 20 degree centigrade

  4. zero degree centigrade
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freezing point is the temperature where a liquid converts into solid. Water converts into ice at zero degrees centigrade. So degree zero centigrade is the freezing point of water. Hence option $D$ is correct.

Multiple choice physics upthrust in fluids, archimedes' principle and floatation upthrust is equal to the weight of displaced liquid pressure in fluids buoyancy

A block of ice of density $0.9\ gm\ cc^{-1}$ and of volume $100\ cc$ floats in water. Then volume of ice inside the water 

  1. $10\ cc$
  2. $90\ cc$
  3. $50\ cc$
  4. $9\ cc$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to the law of flotation, the weight of the floating object equals the weight of the displaced liquid. Therefore, Density_ice * Volume_ice = Density_water * Volume_submerged. Given 0.9 * 100 = 1 * Volume_submerged, the submerged volume is 90 cc.

Multiple choice physics heat - measurement introduction to temperature application of various thermometric scales different types of thermometers

150 g of ice is mixed with 100 g of water at temperature $80^oC$. The latent heat of ice is 80 ca/g and the specific heat of water is $1 cal/g-^oC$. Assuming no heat loss to the environment, the amount of ice which does not melt is

  1. 100 g

  2. 0 g

  3. 150 g

  4. 50 g
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Heat given by water $=100\times 1\times 800=8000 cal$
Heat taken by ice $=8000 cal=m\times 80$
$m=100 gm$
So amount of ice which does not melt $=150-100=50 gm$.

Multiple choice physics heat and temperature thermal expansion in liquids anomalous expansion of water thermal expansion in solids, liquids and gases

A weight thermometer contains 52 gms of a liquid at 10$^{0}$C. When it is heated to 110$^{0}$C, 2 gm of the liquid is expelled. The coefficient of real expansion of the liquid is [$\alpha $ of glass is $9\times 10^{-6/0}C$]

  1. $27\times 10^{-6/0}C$
  2. $412\times 10^{-6/0}C$
  3. $373\times 10^{-6/0}C$

  4. 0
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$V _{expelled} = V _0(\gamma _l -\gamma _g)\Delta T$
$ \Rightarrow  2 = 52 \times ( \gamma _l -3 \times \alpha _g)\times(110-10)$
$ \Rightarrow 2 =52 \times (\gamma _l - 3 \times  9 \times 10^{-6} ) \times 100$
$ \Rightarrow \gamma _l = \frac{2}{52} \times 10^{-2} + 27 \times 10^{-6}=385 \times 10^{-6} + 27 \times 10^{-6}=412 \times 10^{-6}$

Multiple choice physics heat and temperature thermal expansion in liquids anomalous expansion of water thermal expansion in solids, liquids and gases

When a liquid in a glass vessel is heated, its apparent expansion is $10.30\times 10^{-4}/^o$ C. Same liquid when heated in a metallic vessel, its apparent expansion is $10.06\times 10^{-4}/^o$ C. The coefficient of linear expansion of metal is :

($\alpha   _{glass}=9\times 10^{-6}/^o$ C)

  1. $51\times 10^{-6}/^oC$
  2. $43\times 10^{-6}/^oC$
  3. $25\times 10^{-6}/^oC$
  4. $17\times 10^{-6}/^oC$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

${\gamma} _r={{\gamma} _{a1}} +{\gamma} _{glass}={{\gamma} _{a2}} +{\gamma} _{metal}$  ......(1)
where ${{\gamma} _{a1}}$ is the apparent  expansion coefficients when the the liquid is kept in the glass container and ${{\gamma} _{a2}}$is the apparent expansion coefficients when the the liquid is kept in the metal container
Given,
${{\gamma} _{a1}}=10.30 \times {10}^{-4}$
${{\gamma} _{a2}}=10.06 \times {10}^{-4}$
${\alpha} _{glass}=9 \times {10}^{-6}$
${\gamma} _{glass}=3{\alpha} _{glass}=27 \times {10}^{-6}$
${\gamma} _{metal}=3{\alpha} _{metal}$


Substituting the values in (1)
$10.30 \times {10}^{-4} + 27 \times {10}^{-6}=10.06 \times {10}^{-4} + 3{\alpha} _{metal}$
$ \Rightarrow 24 \times {10}^{-6}  + 27 \times{10}^{-6} = 3{\alpha} _{metal}$
$ \Rightarrow {\alpha} _{metal}=(\dfrac{51}{3}){10}^{-6}=17 \times {10}^{-6}$

Multiple choice chemistry element, compound and mixture different types of solutions various mixtures introduction to solutions

Which of the following is used as antifreeze on cars for cooling the engine?

  1. $10\%$ (V/V) ethanol solution in water
  2. $35\%$ (V/V) ethanol solution in glycol
  3. $45\%$ (V/V) ethanol solution in glycol
  4. $20\%$ (V/V) ethanol solution in water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ethanol-water mixtures are commonly used as antifreeze in cooling systems because they lower the freezing point of the coolant.