Heat & Thermodynamics Test paper

Heat & Thermodynamics Test paper

Multiple Choice questions with Single answer

1. Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature T0, while Box B contains one mole of helium at temperature (7/3) T0. The boxes are then put into thermal contact with each other and heat flows between them until
the gases reach a common final temperature. (Ignore the heat capacity of boxes). Then, the final temperature of the gases, T, in terms of T0 is
a)T=5/2T0
b.T=3/7T0
c.T=7/3T0
d.T=3/2T0

2.According to Newton’s law of cooling, the rate of cooling of a body is proportional to (&#96T)n, where &#96T is the difference of the temperature of the body and the surroundings, and n is equal to
(A) two
(B) three
(C) four
(D) one

3.The pressure of the gas in constant volume gas thermometer are 80 cm,90cm and 100cm of mercury at the ice point,the steam point and in a heated wax bath resp.Find the temperature of the wax bath
a)200&#176 C
b)201&#176 C
c)202&#176 C
d) none of the above

4.The pressure P of one mole of gas varies with volume V as
P=4-3V2
Highest absolute temperature to gas can be heated is
a.16/9R
b.9/16R
c 1/16R
d None of the above

5.A sphere,a cube and a circular plate have the same mass and are made of same material.All of them are at the same temperature T.Which one will have maximum rate of cooling.
a. Sphere
b Cube
c. Circular plate
d. All will have same rate of cooling

Multiple Choice questions with More than one answer

6.For an ideal gas
a) Heat added or Heat taken is not null in adiabatic process
b) Internal energy does not change in the isothermal process
c) Change is internal energy is zero in the cyclic process
d. None of the above

7).In which of the following process,convection does takes place
a. sea and land breeze
b.boiling of the water
c.heating air around the furnace
d.warming of glass of bulb due to filament

8)if a gas has n degrees of freedom.Then the expression (Cp/Cp) +1 is equal to
a) 2(1/n +1)
b) 2(n + 1/2)
c) 2+n/2
d) none of the above

Assertion and Reason
a) Statement I is true ,statement II is true ,statement II is correct explanation for statement I
b) Statement I is true ,statement II is true ,statement II is not a correct explanation for statement I
c) Statement I is true,Statement II is false
d) Statement I is False,Statement II is True

9. STATEMENT 1:The molar specific heat capacity of the ideal gas in isothermal process is infinity
STATEMENT 2:Heat transfer is non zero in the Isothermal process

10.STATEMENT 1:Equation of state for a real gas is (P+a/V2)(V-b)=nRT

STATEMENT 2: Molecular attraction is not negligible and the size of molecules are not negligible in comparison to average separation between them

11.STATEMENT 1:Root mean square velocity of the gas does not change in a Isothermal process
STATEMENT 2: Isothermal process may be achieved by immersing the system in large reservoir and performing the process slowly

Matrix Match type
12 Three identical cylinder A1,A2,A3 contains equal moles of Helium,Nitrogen,Carbon dioxide at the same temperature

Match the column I to column II

A)Transnational Energy is maximum in the cylinder
B)Total energy is minimum in the cylinder
C)Root mean square velocity is maximum in the cylinder
D)Mean speed will be minimum in the cylinder

P) A1
Q) A2
R) A3
S) No appropriate match given

A box Of interior Volume V1 has a heavy airtight hinged lid of mass M and area A.The box contains n1 moles of gas at Temperature T0. The box is inside a chamber which also contains additional n2 moles of the same gas at the same temperature..The gas in the chamber occupies the volume V2.

13 find the pressure of the gas in the box
a)n1RT0/V1
b)n2RT0/V2
c)(n1+n2)RT/(V1+V2)
d) none of the above.

14 find the pressure of the gas in the chamber
a)n1RT0/V1
b)n2RT0/V2
c)(n1+n2)RT/(V1+V2)
d) none of the above.

15. Initially the hinged lid is closed.Then which of these expression is true
a.(n1RT0/V1) -(n2RT0/V2) <=Mg/A
b. (n1RT0/V1) -(n2RT0/V2) => Mg/A
c. (n2RT0/V2) -(n1RT0/V1) => Mg/A
d. (n2RT0/V2) -(n1RT0/V1) <= Mg/A

16.If the whole system is heated,at what temperature T will the gas pressure lift the hinged lid
a)T=Mg/RA(n1/V1 -n2/V2)
b)T=Mg/RA(n2/V2 -n1/V1)
c)T=Mg/RA(n1/V1 +n2/V2)
d) None of the above

Multiple Choice questions with Single answer

17.

“Heat cannot by itself flow from a body at lower temperature to a body at higher temperature” is a statement of consequence of
(A) second law of thermodynamics
(B) conservation of momentum
(C) conservation of mass
(D) first law of thermodynamics.

Ans Second law of thermodynamics.

18. During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio Cp/CV for the gas is
(A) 4/3
(B) 2
(C) 5/3
(D) 3/2

Ans A.

19. Which of the following parameters does not characterize the thermodynamic state of matter?
(A) temperature
(B) pressure
(C) work
(D) volume

Ans C.

20.
One mole of ideal mono atomic gas ( Cp/CV= 5/30) is mixed with one mole of diatomic gas (Cp/CV = 7/5). What is Cp/CV for the mixture?
(A) 3/2
(B) 23/15
(C) 35/23
(D) 4/3

Ans A.

21 If the temperature of the sun were to increase from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously will be
(A) 4
(B) 16
(C) 32
(D) 64.

Ans D.

22. Which of the following statements is correct for any thermodynamic system?
(A) The internal energy changes in all processes.
(B) Internal energy and entropy are state functions.
(C) The change in entropy can never be zero.
(D) The work done in an adiabatic process is always zero.

Ans B.

23. The first law of thermodynamics dU=dQ-dW,indicates that when a system goes from its initial state to a final state
a. dU is same for every path
b. dQ is same for evry path
c dQ+dW is same for every path
d dQ-2dW is same for every path