JEE  >  Physics For JEE  >  Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced Download as PDF

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced


Test Description

51 Questions MCQ Test Physics For JEE | Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced for JEE 2022 is part of Physics For JEE preparation. The Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced questions and answers have been prepared according to the JEE exam syllabus.The Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced MCQs are made for JEE 2022 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced below.
Solutions of Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced questions in English are available as part of our Physics For JEE for JEE & Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced solutions in Hindi for Physics For JEE course. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free. Attempt Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced | 51 questions in 100 minutes | Mock test for JEE preparation | Free important questions MCQ to study Physics For JEE for JEE Exam | Download free PDF with solutions
1 Crore+ students have signed up on EduRev. Have you?
Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 1

A constant volume gas thermometer works on (1980)

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 1

Note :  At constant volume, Charle's law is used.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 2

A metal ball immersed in alcohol weighs W1 at 0°C and W2 at 50°C. The coefficient of expansion of cubical the metal is less than that of the alcohal. Assuming that the density of the metal is large compared to that of alcohol, it can be shown that

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 2

W1 = mg – Vdag

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 3

A wall has two layers A and B, each made of different material. Both the layers have the same thickness. The thermal conductivity of the meterial of A is twice that of B.Under thermal equilibrium, the temperature difference across the wall is 36°C. The temperature  difference across the layer A is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 3

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 4

An ideal monatomic gas is taken round the cycle ABCDA as shown in the P – V diagram (see Fig.). The  work done during the cycle is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 4

The work done during the cycle = area enclosed in the curve

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 5

If one mole of a monatomic gas   is mixed with one mole of a diatomic gas  , the value of γ for mixture is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 5

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 6

From the following statements concerning ideal gas at any given temperature T, select the correct one(s)

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 6

For an ideal gas PV = nRT

⇒ Coefficient of volume expansion

Note :  Average translation K.E. for O2 is 3/2 KT
(Three degrees of freedom for translational motion).
Now decrease in pressure increases the volume.

⇒ It increases mean free path of the molecules. Also average K.E. does not depend on the gas, so molecules of each component of mixture of gases have same average translational energy.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 7

Three rods of identical cross-sectional area and made from the same metal from the sides of an isosceles traingle ABC, right-angled at B. The points A and B are maintained at temperatures T and (√2) T respectively. In the steady state, the temperature of the point C is Tc. Assuming that only heat conduction takes place, Tc / T is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 7

Heat flow from B to A, A to C and C to B (for steady state condition, ΔQ/Δt is same)

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 8

Two metallic spheres S1 and S2 are made of the same material and have got identical surface finish. The mass of S1 is thrice that of S2. Both the spheres are heated to the same high temperature and placed in the same room having lower temperature but are thermally insulated from each other. The ratio of the initial rate of cooling of S1 to that of S2 is 

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 8

According to Stefan's law

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 9

The average translational kinetic energy of O2 (relative molar mass 32) molecules at a particular temperature is 0.048 eV.
The translational kinetic energy of N2 (relative molar mass 28) molecules in eV at the same temperature is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 9

Average translational kinetic energy of an ideal gas molecule is 3/2 KT which depends on temperature only. Therefore, if temperature is same, translational kinetic energy of O2 and N2 both will be equal.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 10

A vessel contains 1 mole of O2 gas (relative molar mass 32) at a temperature T. The pressure of the gas is P. An identical vessel containing one mole of He gas (relative molar mass 4) at a temperature 2T has a pressure of

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 10

Therefore, if T is doubled, pressure also becomes two times, i.e.., 2P.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 11

A spherical black body with a radius of 12 cm radiates 450 W power at 500 K. if the radius were halved and the temperature doubled, the power radiated in watt would be

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 11

The energy radiated per second by a black body is given by Stefan's Law

Dividing (ii) and (i), we get

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 12

A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity.Then the pressure in the compartment is 

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 12

When a enclosed gas is accelerated in the positive x-direction then the pressure of the gas decreases along the positive x-axis and follows the equation ΔP = – r a dx where r is the density and a the acceleration of the container.
The result will be more pressure on the rear side and less pressure on the front side.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 13

 A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 13

The internal energy of n moles of a gas is

where F = number of degrees of freedom.
Internal energy of 2 moles of oxygen at temperature T is

Internal energy of 4 moles of argon at temperature T is

Total internal energy = 11 RT

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 14

The ratio of the speed of sound in nitrogen gas to that in helium gas, at 300 K is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 14

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 15

 A monatomic ideal gas, initially at temperature T1, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T2 by releasing the piston suddenly. If L1 and L2 are the length of the gas column before and after expansion respectively, 

then is given by

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 15

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 16

A block of ice at –10°C is slowly heated and converted to steam at 100°C. Which of the following curves represents the phenomenon qualitatively ?

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 16

1. The temp. of ice changes from –10°C to 0°C.

2. Ice at 0°C melts into water at 0°C.

3. Water at 0°C changes into water at 100°C.

4. Water at 100°C changes into steam at 100°C.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 17

An ideal gas is initially at temperature T and volume V. Its volume is increased by ΔV due to an increase in temperature ΔT, pressure remaining constant. The quantity
varies with temperature as

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 17

We know that V/T = constant

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 18

Starting with the same initial conditions, an ideal gas expands from volume V1 to V2 in three different ways. The work done by the gas is W1 if the process is purely isothermal, W2 if purely isobaric and W3 if purely adiabatic. Then 

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 18

Work done is equal to area under the curve on PV diagram.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 19

The plots of intensity versus wavelength for three black bodies at temperature T1, T2 and T3  respectively are as shown. Their temperatures are such that

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 19

According to Wien's law,λT = constant From graph λ1 < λ3 < λ2

∴T1 > T3 > T2

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 20

Three rods made of same material and having the same cross-section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at 0oC and 90oC respectively. The temperature of the junction of the three rods will be

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 20

Let θ°C be the temperature at B. Let Q is the heat flowing per second from A to B on account of temperature difference.

By symmetry, the same will be the case for heat flow from C to B.

∴ The heat flowing per second from B to D will be

Dividing eq. (ii) by eq. (i)

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 21

In a given process on an ideal gas, dW = 0 and dQ < 0. Then for the gas 

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 21

From the first law of thermodynamics

dQ = dU + dW

Here dW = 0  (given)

∴ dQ = dU

Now since dQ < 0  (given)

∴ dQ is negative

⇒ dU = – ve   ⇒ dU decreases.

⇒ Temperature decreases.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 22

P-V plots for two gases dur ing adiabatic pr ocesses are shown in the figure. Plots 1 and 2 should correspond respectively to

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 22

For adiabatic process 

Also for monoatomic gas 

for diatomic gas

⇒ Graph 1 is for diatomic and graph 2 is for mono atomic.

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 23

When a block of iron floats in mercury at 0oC, fraction k1 of its volume is submerged, while at the temperature 60oC, a fraction k2 is seen to be submerged. If the coefficient of volume expansion of iron is γFe and  that of mercury is γHg, then the ratio k1/k2 can be expressed as

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 23

For equilibrium in case 1 at 0° C Upthrust = Wt. of body

For equilibrium in case 2 at 60° C Note : When the temperature is increased the density will decrease.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 24

An ideal gas is taken through the cycle  as shown in the figure. If the net heat supplied to the gas in the cycle is 5J, the work done by the gas in the process C⇒A is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 24

For cyclic process;

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 25

Which of the followin g graphs cor rectly represents the variation of with P for an ideal gas at constant temperature ?

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 25

PV = constant. Differentiating,

∴ Graph between b and P will be a rectangular hyperbola.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 26

An ideal Black-body at room temperature is thrown into a furnace. It is observed that

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 26

Note :  According to Kirchoff's law, good absorbers are good emitters as well.
At high temperature (in the furnace), since it absorbs more energy, it emits more radiations as well and hence is the brightest.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 27

The graph, shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity and absorptivity power of the two bodies

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 27

The graph sh ows that for the same temperature difference (T2 – T1), less time is taken for x. This means the emissivity is more for x. According to Kirchoff's law, a good emitter is a good absorber as well.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 28

Two rods, one of aluminum and the other made of steel, having initial length l1 and l2 are connected together to form a single rod of length l1 + l2. The coefficients of linear expansion for aluminum and steel are αa and αs and respectively. If the length of each rod increases by the same amount when their temperature are raised by t0C, then find the ratiol1/(l1 + l2)

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 28

The lengths of each rod increases by the same amount

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 29

The PT diagram for an ideal gas is shown in the figure, where AC is an adiabatic process, find the corresponding PV diagram.

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 29

If we study th e P – T gr aph we fin d AB to be a isothermal process, AC is adiabatic process given. Also for an expansion process, the slope of adiabatic curve is more (or we can say that the area under the P – V graph for isothermal process is more than adiabatic process for same increase in volume).
Only graph (b) fits the above criteria.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 30

2 kg of ice at –200C is mixed with 5kg of water at 200C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water remaining in the container. It is given that the specific heats of water & ice are 1kcal/kg/0C & 0.5 kcal/kg/0C while the latent heat of fusion of ice is 80 kcal/kg

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 30

Heat required to convert 5 kg of water at 20°C to 5 kg of water at 0°C

Heat released by 2 kg. Ice at – 20°C to convert into 2 kg of ice at 0°C

How much ice at 0°C will convert into water at 0°C for giving another 80 kcal of heat

Therefore the amount of water at 0°C

Thus, at equilibrium, we have, [6 kg water at 0°C + 1kg ice at 0°C].

 

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 31

Three discs A, B and C having radii 2, 4, and 6 cm respectively are coated with carbon black. Wavelength for maximum intensity for the three discs are 300, 400 and 500 nm respectively. If QA, QB and QC are power emitted by A, B and D respectively, then

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 31

We know that λmT = Constant

From comparison QB is maximum.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 32

If liquefied oxygen at 1 atmospheric pressure is heated from 50 k to 300 k by supplying heat at constant rate. The graph of temperature vs time will be

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 32

∴ From 50 K to boiling temperature, T increases linearly.
During boiling, equation is Q = mL Temperature remains constant till boiling is complete After that, again eqn. (i) is followed and temperature increases linearly.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 33

Two identical rods are connected between two containers one of them is at 100ºC and another is at 0ºC. If rods are connected in parallel then the rate of melting of ice is q1 gm/ sec. If they are connected in series then the rate is q2. The ratio q2/ q1 is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 33

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 34

An ideal gas is initially at P1, V1 is expanded to P2, V2 and then compressed adiabatically to the same volume V1 and pressure P3. If W is the net work done by the gas in complete process which of the following is true

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 34

In the first process W is + ve as ΔV is positive, in the second process W is – ve as ΔV is – ve and area under the curve of second process is more

∴ Net Work  < 0 and also P3 > P1.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 35

Variation of radiant energy emitted by sun, filament of tungsten lamp and welding arc as a function of its wavelength is shown in figure. Which of the following option is the correct match ?

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 35

 According to Wein's displacement law

The temperature of Sun is higher than that of welding arc which in turn is greater than tungsten filament.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 36

 In which of the following process, con vection does not take place primarily

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 36

Heat transfer of glass bulb from filament is through radiation. A medium is required for convection process. As a bulb is almost evacuated, heat from the filament is transmitted through radiation.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 37

A spherical body of area A and emissivity e = 0.6 is kept inside a perfectly black body. Total heat radiated by the body at temperature T

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 37

When a non black body is placed inside a hollow enclosure, the total radiation from the body is the sum of what it would emit in the open ( with ϵ<1 ) and the part of the incident radiation from the walls reflected by it. The two add up to a black body radiation.
Hence the total radiation emitted by the body is 1.0ϵAT4.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 38

Calorie is defined as the amount of heat required to raise temperature of 1 g of water by 1oC and it is defined under which of the following conditions?

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 38

1 Calor ie is th e amoun t of heat required to raise temperature of 1 gm of water from 14.5°C to 15.5°C at 760 mm of Hg.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 39

Water of volume 2 litre in a container is heated with a coil of 1 kW at 27 oC. The lid of the container is open and energy dissipates at rate of 160 J/s. In how much time temperature will rise from 27oC to 77oC [Given specific heat of water is 4.2 kJ/kg]

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 39

As shown in the figure, the net heat absorbed by the water to raise its temperature = (1000 – 160) = 840 J/s Now, the heat required to raise the temperature of water from 27°

C to 77°C is

Q = mcΔt = 2 × 4200 × 50 J 

Therefore the time required

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 40

Water is filled up to a height h in a beaker of radius R as shown in the figure. The density of water is r, the surface tension of water is T and the atmospheric pressure is P0.
Consider a vertical section ABCD of the water column through a diameter of the beaker. The force on water on one side of this section by water on the other side of this section has magnitude

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 40

Note : In the first part the force is created due to pressure and in the second part the force is due to surface tension T.

∴ Force = 2P0Rh + Rrgh2 – 2RT

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 41

An ideal gas is expanding such that PT2 = constant. The coefficient of volume expansion of the gas is –

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 41

PT2 = constant (given) Also for an ideal gas PV/T= constt

From the above two equations, after eliminating P.

 

We know that change in volume due to thermal expansion is given by dV where γ = coefficient of volume expansion.
From (i) and (ii)

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 42

A real gas behaves like an ideal gas if its 

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 42

A real gas behaves as an ideal gas when the average distance between the gas molecules is large enough so that (i) the force of attraction between the gas molecules becomes almost zero (ii) the actual volume of the gas molecules is negligible as compared to the occupied volume of the gas.
The above conditions are true for low pressure and high temperature.

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 43

5.6 liter of helium gas at STP is adiabatically compressed to 0.7 liter. Taking the initial temperature to be T1, the work done in the process is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 43

 Initially

The number of moles of gas is 

Finally (after adiabatic compression) V2 = 0.7l For adiabatic compression 

 We know that work done in adiabatic process is

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 44

A mixture of 2 moles of helium gas (atomic mass = 4 amu) and 1 mole of argon gas (atomic mass = 40 amu) is kept at 300 K in a container. The ratio of the rms speeds

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 44

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 45

Two moles of ideal helium gas are in a rubber balloon at 30°C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35°C. The amount of heat required in raising the temperature is nearly (take R = 8.31 J/mol.K)

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 45

The heat is supplied at constant pressure.
Therefore

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 46

Two rectangular blocks, having identical dimensions, can be arranged either in configuration-I or in configuration-II as shown in the figure. One of the blocks has thermal conductivity k and the other 2k. The temperature difference between the ends along the x-axis is the same in both the configurations. It takes 9 s to transport a certain amount of heat from the hot end to the cold end in the configuration-I.
The time to transport the same amount of heat in the configuration-II is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 46

Where k1 and k2 are the equivalent conductivities in configuration I and II respectively.
For configuration I :

 

For configuration II :

option (a) is correct

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 47

Two non-reactive monoatomic ideal gases have their atomic masses in the ratio 2 : 3. The ratio of their partial pressures, when enclosed in a vessel kept at a constant temperature, is 4 : 3. The ratio of their densities is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 47

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 48

Parallel rays of light of intensity I = 912 Wm–2 are incident on a spherical black body kept in surroundings of temperature 300 K. Take Stefan-Boltzmann constant s = 5.7 × 10–8 Wm–2K–4 and assume that the energy exchange with the surroundings is only through radiation. The final steady state temperature of the black body is close to

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 48

In steady state Energy lost = Energy gained

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 49

A water cooler of storage capacity 120 litres can cool water at a constant rate of P watts. In a closed circulation system (as shown schematically in the figure), the water from the cooler is used to cool an external device that generates constantly 3 kW of heat (thermal load). The temperature of water fed into the device cannot exceed 30°C and the entire stored 120 litres of water is initially cooled to 10°C. The entire system is thermally insulated. The minimum value of P (in watts) for which the device can be operated for 3 hours is

(Specific heat of water is 4.2 kJ kg–1K–1 and the density of water is 1000 kg m–3)

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 49

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 50

A gas is enclosed in a cylinder with a movable frictionless piston. Its initial thermodynamic state at pressure Pi = 105 Pa and volume Vi = 10–3 m3 changes to a final state at Pf = (1/ 32) × 105 Pa and Vf = 8 × 10–3 m3 in an adiabatic quasi-static process, such that P3V5 = constant. Consider another thermodynamic process that brings the system from the same initial state to the same final state in two steps: an isobaric expansion at Pi followed by an isochoric (isovolumetric) process at volume Vf . The amount of heat supplied to the system in the two-step process is approximately

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 50

For adiabatic process

From first law of thermodynamics 

Now applying first law of thermodynamics for process

 

Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 51

The ends Q and R of two thin wires, PQ and RS, are  soldered (joined) together. Initially each of the wires has a length of 1 m at 10°C. Now the end P is maintained at 10°C, while the end S is heated and maintained at 400 °C. The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ is twice that of the wire RS and the coefficient of linear thermal expansion of PQ is 1.2 × 10–5 K–1, the change in length of the wire PQ is

Detailed Solution for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced - Question 51

The heat flow rate is same

The temperature gradient access Pd is

Therefore change temperature at a cross-section M distant ‘x’ from P is

Extension in a small elemental length ‘dx’ is

 

257 videos|633 docs|256 tests
Use Code STAYHOME200 and get INR 200 additional OFF
Use Coupon Code
Information about Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced Page
In this test you can find the Exam questions for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced solved & explained in the simplest way possible. Besides giving Questions and answers for Test: Single Correct MCQs: Heat & Thermodynamics | JEE Advanced, EduRev gives you an ample number of Online tests for practice