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 chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

At what temperature ,water have maximum density?

  1. $0^oC$
  2. $4^oC$
  3. $30^oC$
  4. $25^oC$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water exhibits anomalous expansion; it contracts as it cools until it reaches 4 degrees Celsius, after which it begins to expand as it cools further toward freezing. Therefore, its density is highest at 4 degrees Celsius.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

Water is cooled from $4^{\circ}C$ to $0^{\circ}C$. It will:

  1. contract

  2. expand

  3. first contract, then expand

  4. first expand, then contract
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water is cooled from $4^{\circ}C$ to $0^{\circ}C$. It is called "Anomalous expansion of water", i.e. The expansion between 4 and 0 is due to the formation of larger clusters in the water molecules.
When water molecules go from $4^{\circ}C$ to $0^{\circ}C$, they are forming groups in small lattices, what increases volume and decreases density. When water ices, then all their molecules are forming that lattice, as mineral crystals do, with the volume expanded.
Above $4^{\circ}C$, thermal expansion sets as thermal vibrations of the OH bonds of water becomes more vigorous, tending to shove the molecules farther apart and water expands.
As a result of this water at $4^{\circ}C$ is denser than that at $0^{\circ}C$. This causes floating of ice on water during winter. Bursting of pipes is also due to anomalous expansion.
Thus, Option B is correct.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

A teacher one day pointed out to his students the peculiar fact that water is a unique liquid that freezes exactly at $0^oC$ and boils exactly at $100^oC$. He asked the students to find the correct statement based on this fact.


Which of the statements is true regarding the above fact?

  1. Water dissolves anything however sparingly the dissolution may be.

  2. Water is a polar molecule.

  3. Boiling and freezing temperatures of water were used to define a temperature scale.

  4. Liquid water is denser than ice.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option (C) is correct.
Boiling and freezing temperatures of water were used to define a temperature scale.The scaling of zero degree centigrade is based on this fact.

Multiple choice chemistry properties of natural resources conservation of water and recycling properties of water structure and properties of water

The density of water is not same at all temperatures because of its anomalous expansion. The density is maximum at:

  1. $0^{\circ}C$
  2. $4^{\circ}C$
  3. $40^{\circ}C$
  4. $100^{\circ}C$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Density of water is maximum at $4^{\circ}C$. 

On cooling from  $4^{\circ}C$ to $0^{\circ}C$ it expands and on heating from $0^{\circ}C$ to $4^{\circ}C$ it contracts. 
On heating above $4^{\circ}C$ it expands.

Multiple choice chemistry petrochemicals and polymers petroleum properties of alkanes petroleum and natural gas rocks and minerals

During fractional distillation, the crude petroleum is heated to a temperature of about:

  1. $600^{\circ} C$
  2. $400$ to $ 500^{\circ}C$
  3. $200^{\circ}C$
  4. $100^{\circ}C$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fractional distillation of crude oil involves heating it to temperatures typically between 350 and 400 degrees Celsius to separate components based on boiling points. Option B is the closest standard range provided in educational materials.

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

Icc of water at $ 100^o C $ is given 540 cal of heat and the steam formed accupies 167 Icc at the atmospheric pressure. Then workdone against atmospheric pressure in this process is nearly.

  1. 540 cal

  2. 500 cal

  3. 40 cal

  4. 100 cal
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Work done against atmospheric pressure is W = P * delta_V. Given P = 1 atm = 1.013 * 10^5 Pa and the change in volume (steam volume - water volume), the work is approximately 40 cal.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

Water falls from a height 500 m. What is the rise in  temperature of water at bottom if whole energy remains in the water?

  1. $0.96^0C$
  2. $1.02^oC$
  3. $1.17^oC$
  4. $0.23^oC$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Water is at height $(h) = 500 \,m$.
Potential energy $= mgh$
$= 1 \times 9.81 \times 500$
$= 4905 \,J/litre$

Specific heat of water $= 4180 \,J/kg \,k$.
So, $E = mc \Delta T$.
$4905 = 1 \times 4180 \times \Delta T$
$\Delta T = \dfrac{4905}{4180}$
$\Delta T = 1.16^o C$.
Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

The height of the Niagara falls is $50$ metres, $(1 cal= 4.2 \mathrm\ { J }).$  Assume its mechanical energy can be completely converted into heat energy.

  1. Heat energy gained by each gram of water is $49 \times 10 ^ { 5 }\ \mathrm { cal }$
  2. Rise in temperature of water is $0.166^{ o }\ C/g$
  3. Rise in temperature of water is $0.12^{ o }\ C$
  4. Heal energy gained is $500\ joule/g$
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

$1$ calorie is the heat required to increase the temperature of $1g$ of water by $1 ^ { \circ } \mathrm { C }$ from:

  1. $13.5 ^ { \circ } \mathrm { C } \text { to } 14.5 ^ { \circ } \mathrm { C } \text { at } 76 \mathrm { mm } \text { of } \mathrm { Hg }$
  2. $14.5 ^ { \circ } \mathrm { C } \text { to } 15.5 ^ { \circ } \mathrm { C } \text { at } 760 \mathrm { mm } \text { of } \mathrm { Hg }$
  3. $13.5 ^ { \circ } \mathrm { C } \text { to } 15.5 ^ { \circ } \mathrm { Cat } 76 \mathrm { mm } \text { of } \mathrm { Hg }$
  4. $15.5 ^ { \circ } \mathrm { C } \text { to } 16.5 ^ { \circ } \mathrm { C } \text { at } 700 \mathrm { mm } \text { of } \mathrm { Hg }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

The specific heat capacity of a metal at low temperautre (T) is given as $C _ { p } \left( k \sqrt { k } - 1 k g ^ { - 1 } \right) = 32 \left( \frac { T } { 400 } \right) ^ { 3 }$ A 100 gram vessel of this metal is to be cooled from $20 ^ { \circ } K$ to $4 ^ { \circ } \mathrm { K }$ by a special refrigerator operating at room temperature $\left( 27 ^ { \circ } \mathrm { C } \right) .$ The amount of work required to cool the vessel is:-

  1. equal to 0.002$\mathrm { kJ }$
  2. greater than 0.148$\mathrm { kJ }$
  3. between 0.148$\mathrm { kJ }$ and 0.028$\mathrm { kJ }$
  4. less than 0.028$\mathrm { kJ }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

In an energy recycling process, $x _ { g }$ of steam at $100 ^ { \circ } C$ becomes water at $100 ^ { \circ } \mathrm { C }$ which converts $\mathrm { Yg }$ of ice at $0 ^ { \circ } \mathrm { C }$ into water at $100 ^ { \circ } \mathrm { C }$ . The ratio XY will be

  1. $\dfrac { 1 } { 3 }$
  2. $\dfrac { 2 } { 3 }$
  3. $3$
  4. $2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heat released by steam condensing: x * L_v = x * 540 cal. Heat absorbed by ice melting and warming: Y * L_f + Y * 1 * 100 = Y * 80 + Y * 100 = 180Y. Equating: 540x = 180Y. x/Y = 180/540 = 1/3.