Physics

Thermal Properties of Matter

302 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

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 common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

$2\ kg$ of water is converted into steam by boiling at atmospheric pressure. The volume changes from $2\times 10^{-3}\ m^{3}$ to $3.34\ m^{3}$. The work done by the system is about

  1. $-340\ kJ$
  2. $-170\ kJ$
  3. $170\ kJ$
  4. $340\ kJ$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The work done by the system during a isobaric process is calculated as W = P * delta V. Given atmospheric pressure P = 1.013 * 10^5 Pa and volume change delta V = 3.34 - 2 * 10^-3 = 3.338 m^3. Multiplying these gives W = (1.013 * 10^5) * 3.338 approx 3.38 * 10^5 J, which is approximately 340 kJ.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Ratio of primary air to secondary air increases with increase in the rank of coal, because the:

  1. ratio of fixed carbon to volatile matter increases

  2. high rank coals have higher amount of volatile matter

  3. calorific value of the coal increases

  4. oxygen content progressively decreases
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ratio of primary air to secondary air increases with increase in the rank of coal because the ratio of fixed carbon to volatile matter increases.

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

Iron glows in red colour when it is heated to very high temperature because:

  1. Heat we supply consumes red colour at high temperature

  2. Mechanical energy is being converted into heat energy

  3. Light energy is being converted into heat energy

  4. Heat energy is being converted into light energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Iron glows in red colour when it is heated to very high temperature because heat being a form of energy can be transformed into other forms of energy.

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

The temperature of water at the bottom of a waterfall is higher than that of the water at the top, because:

  1. falling water absorbs heat from the sun.

  2. kinetic energy of the falling water is converted into heat.

  3. water at the bottom has greater potential energy.

  4. the rocks on the river bed give out heat.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When water is flowing it posses some kinetic energy and also posses some potential energy wrt to the lower level of the waterfall.

When water fall from higher level its potential energy gets converted to kinetic energy and when water reaches to lower level some part of its kinetic energy gets converted to sound energy amd some to heat energy.
So best possible option is option B.

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

When we rub our hands, which of the following is true?

  1. Mechanical energy converted to heat energy.

  2. kinetic energy converted to heat energy.

  3. Heat energy converted to mechanical energy.

  4. Heat energy converted to kinetic energy.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rubbing hands involves the movement of muscles (mechanical energy), and the friction generated converts that motion into heat energy.

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

When $1\ gm$. of water at $100^{\circ}C$ is converted into steam occupies $1671\ c.c.$ The amount of work done in converting water into steam is

  1. $167\ J$
  2. $180\ J$
  3. $184\ J$
  4. $2098\ J$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The work done in a phase change where volume increases is given by W = P * Delta V. Assuming atmospheric pressure P = 1.013 * 10^5 N/m^2 and the change in volume Delta V = 1671 c.c. = 1671 * 10^-6 m^3, multiplying these gives W = (1.013 * 10^5) * (1671 * 10^-6) = 169 J, which is approximately 167 J considering standard approximations for atmospheric pressure and conversion.

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
B Correct answer
Explanation

By international convention, one calorie is defined precisely as the amount of heat required to raise the temperature of 1 gram of pure water from 14.5 degrees Celsius to 15.5 degrees Celsius at a standard pressure of 760 mm of Hg.

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