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CBSE Questions for Class 11 Engineering Physics Thermal Properties Of Matter Quiz 14 - MCQExams.com

A 20gm bullet whose specific heat is 5000 J/ (kg- oC) and moving at 2000 m/s plunges into a 1.0 kg block of wax whose specific heat is 3000 J/(kg- oC). Both bullet and wax are 25oC and assume that (i) the bullet comes to rest in the wax and (ii) all its kinetic energy goes into heating the wax.  Thermal temperature of the wax in oC is close to
  • 28.1
  • 31.5
  • 37.9
  • 42.1
Two spheres of the same material havethe same radius but one is hollow while the other is solid. Both spheres are heated to same temperature. Then
  • The solid sphere expands more
  • The hollow sphere expands more
  • Expansion is same for both
  • Nothing can be about their relative expansion
A vertical column 50cm long at 50C balances another column of same liquid 80 an long at 1000C The coefficient of absolute expansion of the liquid is 
  • 0.005/C
  • 0.03/0c
  • 0.002/0C
  • 0.0002/C
Calorimeter helps us to determine
  • boiling point
  • melting point
  • specific heat
  • freezing point
If temperature difference between two sides of an iron plate 2 cm thick is 100C and thermal conductivity of iron is 0.02Kcal/smK then heat transmitted through the plate per second per m2 at steady state is:
  • 100Kcal/m2s
  • 10Kcal/m2s
  • 600Kcal/m2s
  • 40Kcal/m2s
What equivalent of calorimeter is :
  • mC1
  • mC1C2
  • mC2C2
  • none of these
Two 50 g ice cubes are placed into 0.2 kg of water in a closed container made of styrofoam. the water is initially a temperature of 150C . the system is allowed to attain equilibrium. the system is allowed to attain equilibrium . the system does not exchange heat with with surrounding . the average specific heat for for ice between 150c and 00C id 2kJkg1K1 latent heat of fusion for ice is is 10003kjkg1 specific heat for water is 4.2kJkg1k1
  • The amount of heat supplied by water to melt ice is 21 kJ
  • The final temperature of the mixture is 12.40C
  • the final temperature of the system is 00C
  • the amount of ice melted is 0.054 kg
Two liquids A and B are at 30C and 20C respectively. When they are mixed in equal masses the temperature of the mixture is found to be 26C . The ratio of specific heats is
  • 4:3
  • 3:4
  • 2:3
  • 3:2
Select the correct statement related to heat
  • Heat is possessed by a body
  • Hot water contains more heat as compared to cold water
  • Heat is a energy which flows due to temperature difference
  • All of these
An electric heater rated as 2 kW is used to heat 200 kg of water from 10C to 70C. Assuming no heat losses, the time take is-
  • 25.2 sec
  • 6×103 sec
  • 25.2×103 sec
  • 25.2×106 sec
One mole of a perfect gas in a cylinder fitted with a piston has a pressure P, volume V and temperature is increased by 1 K keeping pressure constant , the increase in volume is
  • 2V273
  • 2V91
  • V273
  • V
On a hypothetical scale  A  the ice point is  42  and the steam points is  182  For another scale   B,  the ice point is  10  and steam point is  90  If  B  reads  60,  the reading of  A  is,
  • 160
  • 140
  • 120
  • 110
Two identical rods of a metal are welded as shown in figure (a). A certain amount of heat flows through them in 12 min. If the rods are welded as shown in figure (b) then the same amount of heat will flow in 
1475507_9000cd3ad6e94c64902b72c2b1be3594.PNG
  • 1 minute
  • 3 minutes
  • 16 minutes
  • 2 minutes
The figure shows the face and interface temperature of a composite slab containing four layers of two materials having an identical thickness. Under the steady slate conditions, find the value of temperature θ.
1496746_a8c4e943bcdc4e71983a45050c68a6af.PNG
  • 5oC
  • 10oC
  • 15oC
  • 15oC
50 gm of copper is heated to increase its temperature by 10C . If the same quantity of heat is given to 10gm of water, the rise in its temperature is ( Specific heat of copper = 420Joulekg1C1 )
  • 5C
  • 6C
  • 7C
  • 8C
Three slabs of equal area and thickness are arranged as shown in the figure. Find the value of T1 and T2 in steady state:
1508467_c54bc5f2f39f4009bc0045c3d5f806d6.PNG
  • 68oC&52oC
  • 62oC&58oC
  • 60oC&50oC
  • 50oC&30oC
Two rods of the same length and cross-sectional area are joined in series. The thermal conductivity of the rods is in ratio 1:The ends are maintained at a temperature T1 and T2 as shown in the figure. The sides are thermally insulated. If T1 > T2then which of the following graphs represents variation temperature gradient (dTdx) with x in steady state?

1479863_85c6277a7ade49e7a83fa5505bb50e61.png
An ideal gas with pressure P, volume V and temperature T is expanded isothermally to a volume 2V and a final pressure PI. The same gas is expanded adiabatically to a volume 2V, the final pressure is PA. In terms of the ratio of the two specific heats for the gas γ, the ratio PI/PA is:
  • 2γ1
  • 21γ
  • 2γ
  • 2γ
The value of the gas constant (R) calculated from the perfect gas equation is 8.32Joule/gmmolK, whereas its value calculated from the knowledge of Cp and Cv of the gas is 1.98cal/gmmoleK. from this data, the value of J is
  • 4.16J/cal
  • 4.18J/cal
  • 4.20J/cal
  • 4.22J/cal
A solid whose volume does not change with temperature floats in a liquid. For two different temperatures t1 andt2 of the liquid, fractions f1 and f2 of the volume of the solid remain submerged in the liquid. The coefficient of volume expansion of the liquid is equal to
  • f1f2f2t1f1t2
  • f1f2f1t1f2t2
  • f1+f2f2t1+f1t2
  • f1+f2f1t1+f2t2
When the temperature difference between in side and outside of a room is 20 the rate of heat flow through a window is 273 J/s. If the temperature difference becomes 20K, the rate of flow of heat through the same window will be: 
  • 253 J/s
  • 273 J/s
  • 293 J/s
  • None of these
On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39W  and 239W respectively. What will be the temperature on the new scale, corresponding to a temperature of 39 on the Celsius scale?
  • 139W
  • 78W
  • 117W
  • 200W
For N2the value of CpCv=
  • 14R
  • R14
  • 28R
  • R28
With rise in temperature, density of a given body change according to one of the following relations 
  • ρ=ρ0[1+γdθ]
  • ρ=ρ0[1γdθ]
  • ρ=ρ0γdθ
  • ρ=ρ0/γdθ
Critical temperature of a gas obeying van der waals' equation is : 
  • 8a27Rb
  • a27b2r
  • 3b
  • 127Rb
One mole  of gas ''A'' and 2 moles of SO2 are placed in a container,gaseous can be:
  • H2
  • CH4
  • He
  • D2
Two materials having coefficients of thermal conductivity 3K and K and thickness 'd' and 3d, respectively, are joined to form a slab as shown in the figure. The temperature of the outer surfaces are θ2 and θ1 respectively, (θ2>θ1). The temperature at the interface is?
1614211_d4f5e272b1884533b68cd3636fe9ca69.png
  • θ2+θ12
  • θ110+9θ210
  • θ13+2θ23
  • θ16+5θ26
The figure shows a system of two thin concentric spherical shells of radii r1andr2 and kept at temperatures T1andT2 respectively. The radial rate of heat in a substance between the two concentric spheres is proportional to :
1540226_892850f25f9f4b08ba1d8e3292e313aa.png
  • r1r2(r2r1)
  • (r2r1)
  • (r2r1)r1r2
  • log(r2r1)
When water is heated from 00C to 100C, its volume -
  • increases
  • decreases
  • does not change
  • first decreases and then increases
In a Carnot engine, when heat is absorbed from the source, temperature of source 
  • Increases
  • Decreases
  • Remains constant
  • Cannot say
At ordinary temperature,the molecule of an ideal gas have only translation and rotational kinetic energies. At high temperature,they may have vibrational energy.As a result of this, at higher temperature molar specific heat capacity at constant volume Cv for a diatomic gas is
  • =5R2
  • <5R2
  • >3R2
  • =3R2
A compound rod is formed of a steel core of diameter 1cm and outer casing is of copper, whose outer diameter is 2cm. The length of this compound rod is 2m and one end is maintained as 100C, and the end is at 0C. If the outer surface of the rod is thermally insulated, then heat current in the rod will be:
(Given : Thermal conductivity of steel =12 cal/mKs, thermal conductivity of copper =92 cal/mKs).
  • 2 cal/s
  • 1.13 cal/s
  • 1.42 cal/s
  • 2.68 cal/s
If the thermal conductivity of the material of the rod of length l, is K, then the rate of heat flow through a tapering rod, tapering from radius r1 and r2, if the temperature of the ends are maintained at T1 and T2, is
  • πKr1r2(T1+T2)l
  • πKr1r2(T1T2)l
  • πKr1r2(T1T2)2l
  • πKr21(T1+T2)l
Five wires each of cross-sectional area A and length l are combined as shown in figure. The thermal conductivity of copper and steel are K1 and K2 respectively. If A is maintained at 100C and C is maintained at 0C. The rate emitted at C is : (assume the curve surfaces of rods are thermally insulated).
1703846_d9b4574a6f8e466687c7bececce017a1.png
  • 50A(K1+K2)l
  • 100A(K1+K2)l
  • A(K1+K2)l
  • None of these
Which of the following does not affect the distribution of insolation?
  • Altitude
  • Angle of sun's rays
  • Length of the day
  • Ocean currents
A uniform cylindrical rod of length L and radius r, is made from a material whose Young's modulus of Elasticity equals Y. When this rod is heated by temperature T and simultaneously subjected to a net longitudinal compressional force F, its length remains unchanged. The coefficient of volume expansion, of the material of the rod, is (nearly) equals to : 
  • F/(3πr2YT)
  • 3F/(πr2YT)
  • 6F/(πr2YT)
  • 9F/(πr2YT)
The ice is filled in a hollow glass sphere of thickness 2\ mm and external radius 10\ cm. This hollow glass sphere with ice now placed in a bath containing boiling water at 100^{\circ}C. The rate at which ice melts, is: (Neglect volume change in ice)
(Given : thermal conductivity of glass 1.1\ W/m/K, latent heat of ice = 336\times 10^{3} J/kg).
  • \dfrac {m}{t} = 0.01\ kg/s
  • \dfrac {m}{t} = 0.002\ kg/s
  • \dfrac {m}{t} = 0.02\ kg/s
  • \dfrac {m}{t} = 0.001\ kg/s
A block of ice at 0^{\circ} rests on the upper surface of the slab of stone of area 3600\ cm^{2} and thickness of 10\ cm. The slab is exposed on the lower surface to steam at 100^{\circ}C. If 4800\ g of ice is melted in one hour, then the thermal conductivity of stone is:
(Given: The latent heat of fusion of ice = 80\ cal/gm).
  • K = 2.96\times 10^{-3} cal/ cm\ s^{\circ}C
  • K = 1.96\times 10^{-3} cal/ cm\ s^{\circ}C
  • K = 0.96\times 10^{-3} cal/ cm\ s^{\circ}C
  • None of the above
The value of C_p - C_v is 1:00 R for a gas sample in state A and is 1.08 R in state B. Let P_A, P_a denote the pressures and T_A\ and\ T_a denote the temperature of the states A and a respectively.Most likely
  • P_A < P_a\ and\ T_A > T_e
  • P_A > P_a\ and\ T_A < T_a
  • P_A = P_a\ and\ T_A < T_a
  • p_A > P_a\ and\ T_A = T_e
One mole of an ideal gas passes through a process where pressure and volume obey the relation P = P_0 \left[1 - \dfrac{1}{2} \left(\dfrac{V_0}{V} \right)^2 \right]. Here P_0 and V_0 are constants . Calculate the change in the temperature of the gas if its volume change from V_o to 2 V_o.
  • \dfrac{1}{2} \dfrac{P_o V_o}{R}
  • \dfrac{3}{4} \dfrac{P_o V_o}{R}
  • \dfrac{5}{4} \dfrac{P_o V_o}{R}
  • \dfrac{1}{4} \dfrac{P_oV_o}{R}
A heater of constant power is used to boil water in a pot. During heating, temperature of water increases from 60^o C to 65^o C in 1.0 \ min. When the heater is switched off, temperature of water falls from 65^o C to 60^o C in 9.0 \ min. If rate of heat dissipation to the surrounding remains almost constant, what proportion of heat received by water during heating would be dissipated to the surroundings?
  • 9\%
  • 10\%
  • 12.5\%
  • 15\%
After the steady state conditions are reached, the temperature of the spherical end of the rod, T_{S} is:
  • T_{S}=T-\dfrac{P(L+r)}{KA}
  • T_{S}=0^{o}C
  • T_{S}=\dfrac{PL}{KA}
  • T_{S}=T-\dfrac{PL}{KA}
If the metal sphere attached at the end of the copper rod is made of brass, whose thermal conductivity is K_{b}<K, then which of the following statements is true?
  • The temperature of the sphere will, under steady state conditions, continue to be T_{B}
  • The power that will be radiated out from the sphere will still be P_{S}
  • It will take smaller time for steady state conditions to be reaches
  • The rate of thermal energy transmitted across the copper rod, under steady state, will be reduced
An alternative method for keeping the tea hot would be to place the teapot on a 10 pound block that has been heated in an oven to 300^{o}C. A block of which of the following substance would best  be able to keep the tea hot?
  • copper (specific heat =0.39\ J/g\ K)
  • granite (specific heat =0.79\ J /g\ K)
  • iron (specific heat =0.45\ J/g\ K)
  • pewter (specific heat =0.17\ J/g\ K)
The volume of an air bubble is doubled as it rises from the bottom of a lake to its surface. If the atmosphere pressure is Hm of mercury and the density of mercury is n times that of lake water the depth of lake is :
  • H/n
  • nH/2
  • nH
  • 2nH
What is the final temperature of the system ?
  • 48^{o}C
  • 72^{o}C
  • 94^{o}C
  • 100^{o}C
The net power that will be radiated out, P_{S}, from the sphere after steady state conditions are reached is:
  • P_{S}=P
  • P_{S}=\dfrac{PA}{4\pi r^{2}}
  • P_{S}=0
  • P_{S}=\sigma \varepsilon T_{5}^{4}
If, after some of the tea has been transferred to the thermos (as described in the passage), the teapot with its contents (at a temperature of 80^{o}C) was placed or the insulated warmer for 5 minutes, what would be the temperature at the end of this 5 minutes period (Assume that no significant heat transfer occurs with the surrounding):
  • 80.7\ ^{o}C
  • 82.5\ ^{o}C
  • 83.2\ ^{o}C
  • 95.2\ ^{o}C
Three rods of identical cross-sectional area and made from the same metal from the sides of an isosceles triangle ABC right angled at B. The points A and B are maintained at temperatures T and \sqrt 2 T respectively in the steady state. Assuming that only heat conduction takes place temperature of point C will be:
1738562_dade4ce2033e49a99fca179feb317f19.png
  • \dfrac {3T}{\sqrt 2 +1}
  • \dfrac {T}{\sqrt 2 +1}
  • \dfrac {T}{\sqrt 3 (\sqrt 2 +1)}
  • \dfrac {T}{\sqrt 2 -1}
Four identical rods which have thermally insulated lateral surfaces are joined at point A. Points B, C, D and E are connected to larger reservoirs. If heat flows into the junction from point B at rate of 1\ W and from point C at 3\ W inside, flows out from D at 5\ W, which relation (s) is /are correct for temperature of these points?
1738566_4b982bcac06f49c1a865c291b53b42bc.png
  • T_A < T_E
  • T_B =T_C
  • T_C > T_D
  • T_B = T_E
0:0:2


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