CBSE Questions for Class 11 Engineering Physics Thermal Properties Of Matter Quiz 10 - MCQExams.com

A lead bullet, of initial temperature $$27 ^ { \circ } C$$ and speed $$'v'$$ kmph pnetrates into a solid object and melts. If $$50\%$$ of the kinetic energy is used to heat it, The value of $$V$$ is kmph is (for leads melting point  = 600 K, latent heat of fusion = $$2.5 \times 10 ^ { 4 } J$$ $$\mathrm { Kg } ^ { - 1 }$$ : specific heat = $$125 J$$ $$k g ^ { - 1 } K ^ { - 1 }$$
  • 1800
  • 3600
  • 1200
  • 1000
The heat transferred by the radiator of a refrigerator is
  • more than that at the freezer
  • less than that at the freezer
  • the same as that at the freezer
  • none of these
If the ratio of the coefficient of thermal conductivity of silver and copper is $$10: 9$$, then the ratio of the lengths up to which was will melt in Ingen Hauz experiment will be 
  • $$6: 10$$
  • $$\sqrt{10}:3$$
  • $$100: 81$$
  • $$81: 100$$
Density of substance at $$0^oC$$ is 10 gm/cc and at $$100^oC$$, its density is 9.7 gm/cc. The coefficient of linear expansion of the substance will be -
  • $$10^2$$
  • $$10^{-2}$$
  • $$10^{-3}$$
  • $$10^{-4}$$
When $$2 gm$$ of gas is introduced into an evacuated flask kept at $$25^oC$$ the pressure is found to be one atmosphere. If $$3 gm$$ of another gas added to the same flask the pressure becomes $$1.5$$ atmospheres. The ratio of the molecular weights of there gases will be
  • $$1:3$$
  • $$3:1$$
  • $$1:2$$
  • $$3:2$$
Two spherical vessel of equal volumes, are connected by a narrow tube. The apparatus contains an ideal gas at one atmosphere and 300K. Now if one vessel is immersed in a bath of constant temperature 600 K and the other in a bath of constant temperature 300 K. Then the common pressure will be
1239841_9b0d4ab4a8f6437fb5d9ece4c50af84e.png
  • $$1 atm$$
  • $$4/5 atm$$
  • $$4/3 atm$$
  • $$3/4 atm$$
A real gas most closely approaches the behaviour of an ideal gas at :
  • 15 atm and 200 K
  • 1 atm and 273 K
  • 0.5 atm and 500 K
  • 15 atm and 500 K
Two metal sphere have radii $$r$$ and $$2r$$ and they emit thermal radiation with maximum intensities at wavelength $$\lambda$$ and $$2 \lambda$$. The respective ratio of the radiant energy emitted  by them per second will be
  • $$4:1$$
  • $$1:4$$
  • $$16:1$$
  • $$8:1$$
A body at $$50^oC$$ cools in a surroundings maintained at $$30^oC$$. The temperature at which the rate of cooling is half that of the beginning is:
  • $$16.3^oC$$
  • $$26.3^oC$$
  • $$40^oC$$
  • $$46.3^oC$$
The thermal radiations are similar to
  • $$X-$$rays
  • Cathode rays
  • $$\alpha -$$rays
  • Sound waves
Air is filled in a motor tube at $$27^{o}C$$ and at a pressure of $$2$$ atmospheres. The tube suddenly bursts, then temperature of air is [Given $$\gamma$$ of air $$=1.251$$ ]
  • $$27.5^{o}K$$
  • $$75^{o}K$$
  • $$240^{0}K$$
  • $$150^{o}K$$
If the $$K_{a}$$ radiation of Mo has a wavelength of 0.71 $$A_{0}$$. The wavelength of the corresponding radiation of $$Cu :- [Z_{Mo}=42, Z_{Cu}=29]$$
  • 0.52 $$A_{0}$$
  • 1.52 $$A_{0}$$
  • 2.52$$A_{0}$$
  • 3.52 $$A_{0}$$
Heat is added to an ideal gas, and the gas expands. In such a process the temperature 
  • must always increase
  • will remain the same if the work done equals the heat added
  • must always decrease
  • will remains the same If change in internal energy equals the heat added.
20 g of steam at $${ 100 }^{ \circ  }C$$ is passed into 100 g of ice at $${ 0 }^{ \circ  }C$$. Find the resultant temperature if specific latent heat of steam is 540 cal/g., specific latent heat of ice is 80 cal/g and specific heat of water is $$1 { cal/g }^{ \circ  }C$$
  • $${ 10 }^{ \circ }C$$
  • $${ 20 }^{ \circ }C$$
  • $${ 30 }^{ \circ }C$$
  • $${ 40 }^{ \circ }C$$
The Process of convection is faster than 
  • Conduction
  • Radiation
  • Both conduction and convection
  • Neither conduction nor radiation
Faulty thermo has its fixed pts marked 5g. what is correct temperature in celcius when it reads 5g?
  • $$ 45^0 $$
  • $$ 60^0 $$
  • $$ 75^0 $$
  • none
The energy from the sun reaches the earth by 
  • Conduction
  • Radiation
  • Convection
  • All the above
Which of the following is incorrect relation fot a perfect gas?
  • $${ \quad \left( \frac { \eth U }{ \eth V } \right) }_{ T }=0$$
  • $${ \quad \left( \frac { \eth H }{ \eth P } \right) }_{ T }=0$$
  • $${ \quad \left( \frac { \eth T }{ \eth P } \right) }_{ H }=0$$
  • $${ \quad \left( \frac { \eth U }{ \eth T } \right) }_{ V }=0$$
A solid copper cube and sphere both of same mass and emissivity are heated to same initial temperature and kept under identical conditions. What is the ratio of their initial rate of fall of temperature.
  • $$\left(\dfrac{3}{2\pi}\right)^{\dfrac{3}{2}}$$
  • $$\dfrac{4\pi}{3}\left(\dfrac{3}{2\pi}\right)^{\dfrac{2}{3}}$$
  • $$\left(\dfrac{6}{\pi}\right)^{\dfrac{1}{3}}$$
  • $$\dfrac{3}{2\pi}\left(\dfrac{4}{3}\pi\right)^{\dfrac{1}{3}}$$
An ideal gas is expanding such that $$PT = constant$$. The coefficient of volume expansion of the gas is
  • $$\dfrac {1}{T}$$
  • $$\dfrac {2}{T}$$
  • $$\dfrac {3}{T}$$
  • $$\dfrac {4}{T}$$
$$'n'$$ moles of an ideal gas undergoes a process $$A\rightarrow B$$ as shown in the figure. The maximum temperature of the gas during the process will be :
1253751_287b71a57bbe47b19501c99d9202016b.png
  • $$\cfrac{3P_{0}V_{0}}{2nR}$$
  • $$\cfrac{9P_{0}V_{0}}{2nR}$$
  • $$\cfrac{9P_{0}V_{0}}{nR}$$
  • $$\cfrac{9P_{0}V_{0}}{4nR}$$
Where temperature of a gas, contained in closed vessel is increased by $$5C$$, its pressure increases by $$1%$$.The original temperature of the gas was approx i - mately:- 
  • $$500C$$
  • $$273C$$
  • $$227C$$
  • $$50C$$
For ideal monoatomic gas,the universal gas constant R is n times molar heat capacity at constant pressure $$ C_p $$ Here n is :-
  • 0.67
  • 1.4
  • 0.4
  • 1.67
p-T diagram was obtained when a given mass of gas was heated. During the heating process from the state 1 to state 2 the volume
1279430_9e876bd8edcb4dd0849738ee98b967b9.png
  • remained constant
  • decreased
  • increased
  • changed erratically
Two rods having thermal conductivities in the ratio of 5:3 and having equal length length and equal cross-section are joined by face to face. If the temperature of free end of first rod is $$100^oC$$ and temperature of  free end of second rod is $$20^oc$$, then temperature of the junction, is-
  • $$90^oC$$
  • $$85^oC$$
  • $$70^oC$$
  • $$50^oC$$
Two bodies A and B have emissivities 0.5 ans 0.8 respectively. At some temperatures the two bodies have maximum spectral emissive powers at wavelength 8000 $$\mathring { A } $$ and 4000 $$\mathring { A }$$ respectively. The ratio of their emissive powers at these temperatures is : 
  • $$\dfrac{5}{128}$$
  • 10
  • $$\dfrac{5}{16}$$
  • none of these
 An ideal gas at pressure P is adiabatically compressed so that its density becomes n times the initial value. The final pressure of the gas will be $$ ( \gamma= C_p/C_v) $$ 
  • $$ n^\gamma P $$
  • $$ n^{-\gamma} P $$
  • $$ n^{\gamma-1} P $$
  • $$ n^{1-\gamma} P $$
$$1 $$ mole of a monoatomic gas at temperature $$T_0$$ expand slowly according to the law $$P^2 = T$$. Its final temperature is $$ 2T_o$$ , then heat supplies to the gas is
  • $$\frac{R}{T_o/2}$$
  • $$RT_o$$
  • $$\frac{3}{2} RT_o$$
  • $$2RT_o$$
Rate of emission thermal radiation of a spherical black body of radius $$r$$ is $$H$$. It rate of cooling is $$C$$. Then 
  • $$H\propto \,r$$
  • $$H\propto \,{r^3}$$
  • $$C\,\propto\,\dfrac{1}{r}$$
  • $$C\,\propto \,\dfrac{1}{{{r^2}}}$$
The volume of an ideal gas is 1 litre and its pressure is equal to 72 cm of mercury column. The volume of gas is made $$ 900 cm^3 $$ by compressing it isothermally. The stress of the gas will be 
  • 8 cm (mercury)
  • 7 cm (mercury)
  • 6 cm (mercury)
  • 4 cm (mercury)
Half mole of an ideal monoatomic gas is heated at constant  pressure of 1 atm from $${ 20 }^{ 0 }C$$ to $${ 90 }^{ 0 }C$$ . Work done by gas is close to : ( gas constant R=8.31 j / mol -k ) 
  • 146 j
  • 581 j
  • 73 j
  • 291 j
Who amongst the following shows lowest tendency towards reduction in gaseous state.
  • Se
  • Br
  • I
  • 0
If the temperature difference between the two side of a wall is doubled, its thermal conductivity 
  • Remains same
  • Is doubled
  • Is halved
  • Becomes four times
One mole of an ideal gas expands against a constant external pressure of 1 atm from a volume of $$10d{ m }^{ 3 }$$ to a volume of $$30d{ m }^{ 3 }$$. What would be the work done in joules?
  • $$-2026 J$$
  • $$+2026 J$$
  • $$-1947 J$$
  • $$1648 J$$

In which of the following process, convection does not take place primarily?
  • Sea and land breeze
  • Boiling of water
  • Warming of glass bulb due to filament
  • Heating air around furnace
Coefficient  of real expansion mercury is $$0.18 \times {10^{ - 3}}{/^0}C.$$ if the density of mercury at $${0^0}C$$  is $$13.6 gm/C.C,$$ then is density at $$473K$$ will be$$:$$
  • $$13.11 \%$$
  • $$3.6 \%$$
  • $$36 \%$$
  • $$24.4 \%$$
Which of the curves in figure represents the relation between Celsius and Fahrenheit temperature 
1392375_512df961fabb4fbb873f2bae8326110e.png
  • a
  • b
  • c
  • d
N moles of a monoatomic gas is carried round the reversible rectangular cycle ABCDA as shown in the diagram. The temperature at $$A$$ is $$T _ { 0 }$$ . The thermodynamic efficiency of the cycle is


1372128_34b8ce5be7e548d7bf2db455e8faee63.jpg
  • $$ 15 \%$$
  • $$ 50 \%$$
  • $$ 20 \%$$
  • $$ 25 \%$$
A hetaed smooth metallic body is allowed to cool in air. Which of the following statements about its heat loss is incorrect?
  • Convection currents in the air aid the process of heat loss.
  • Conduction is the main mode of heta loss as the body is a good conductor of heat
  • The rate of heat loss by thermal radiation is increased due to its metallic surface.
  • The rate of heat loss decreases as the temperature of teh body nears room temperature
Gravesande's right-and-ball experiment show that liquids expand on heating.
  • True
  • False
A device in which the loss of heat due to conduction, convection and radiation is minimized is
  • Solar cell
  • Solar cooker
  • Thermometer
  • Thermos flask
Find the amount of work done to increase the temperature of 1 mol of an ideal gas by $$30 ^ { \circ } { C }$$ if it is expanding under the condition $$V \propto T ^ { 2 / 3 }$$ .
  • $$166.2$$ $${ J }$$
  • $$136.2$$ $${ J }$$
  • $$126.2$$ $${ J }$$
  • None of these
In which of the following processes, convection does not take place primarily?
  • Sea and land breeze
  • Boiling of water 
  • Heating air around a furnace
  • Warming of glass of bulb due to filament
An isotropic point source having radiation power P is located on the axis of an ideal circular mirror of radius r .The distance between the source and the plate is l which is much bigger than radius of the plate .Force that the light exerts on the plate is 
1444883_fa2b79cde7654a349da72134eec46476.png
  • $$\cfrac{P}{2c}\left[\cfrac{r^{2}}{l^{2}}\right]$$
  • $$\cfrac{2P}{c}\left[\cfrac{r^{2}}{l^{2}}\right]$$
  • $$\cfrac{P}{c}\left[\cfrac{r^{2}}{l^{2}}\right]$$
  • $$\cfrac{P}{4c}\left[\cfrac{r^{2}}{l^{2}}\right]$$
All bodies radiate heat at all temperature except at
  • $$0^0C$$
  • $$100^0C$$
  • $$0K$$
  • Absolute temperature
The coefficient of cubical expansion of water is zero at: 
  • $$0 ^ { \circ } C$$
  • $$4 ^ { \circ } C$$
  • $$15.5 ^ { \circ } C$$
  • $$-273 ^ { \circ } C$$
The intensity of heat radiation by a point source measured by a thermopile placed at a distance d is $$I$$ , If the distance of thermopile is doubled then the intensity of radiation will be -
  • $$I$$
  • $$2I$$
  • $$I/4$$
  • $$I/2$$
An ideal gas is expanding such that $$P T ^ { 2 } =$$ constant. The coefficient of volume expansion of the gas is
  • $$\dfrac{1}{T}$$
  • $$\dfrac{2}{T}$$
  • $$\dfrac{3}{T}$$
  • $$\dfrac{4}{T}$$
'n' moles of an ideal gas undergoes a process A $$\rightarrow$$B as shown in figure. The maximum temperature of the gas during the process will be :
1510606_1aee17d9910e46f3afd9145d93d9297a.png
  • $$\dfrac{9P_0V_0}{nR}$$
  • $$\dfrac{9P_0V_0}{4nR}$$
  • $$\dfrac{3P_0V_0}{2nR}$$
  • $$\dfrac{9P_0V_0}{2nR}$$
A sphere, a cube and a thin circular plate, all of same material and same mass, are initially heated to same high temperature. Choose the correct statement.
  • The plate will cool fastest and cube the slowest
  • The sphere will cool faster and cube and the slowest
  • The plate will cool faster and sphere the slowest
  • The cube will cool fastest and plate the slowest.
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers