1.
“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.
2. 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.
3. Which of the following parameters does not characterize the thermodynamic state of matter?
(A) temperature
(B) pressure
(C) work
(D) volume
Ans C.
4.
One mole of ideal monoatomic 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.
5 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.
6. 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.
Showing posts with label Thermo Objective for IITJEE. Show all posts
Showing posts with label Thermo Objective for IITJEE. Show all posts
Thursday, 19 June 2008
Wednesday, 6 February 2008
Objective question of Thermodynamics for IITJEE/AIEEE
1. An ideal gas is taken through the cycle abcda.calculate the work done by the gas
a,3pv
b,2pv
c,pv
d,none of the above
2.An ideal gas was taken from state a to state b in three ways...If W1,W2,W3 are workdone by the gas in patch abc,adc and ac respectively.Which one of the following is true
a. W1 > W2 > W3
b. W1 > W3 > W2
c. W3 > W2 > W1
d. None of the above
3. An ideal gas is taken through the cycle aba.calculate the work done by the gas
a 2pv-1/2πv2
b 2pv+1/2πv2
c 2pv
d None of the above
4. N rods of equal length L and equal crossestion area having thermal conductivities from k to nk respectivity are joined together to form rod of length NL.What is the ratio of Thermal conductivity of whole rod to the thermal conductivity of Nth Rod.
a.1/2(n+1)
b.n+1
c.n
d.1
5.The speed of the four molecules are v,2v,3v,4v.What is the rms speed of the gas
a.v√7
b. 7v
c.v√2
d.v√7.5
6.A sample of gas expands from volume V1 to V2.The amount of workdone by the gas is greatest when the expansion is
a. Isothermal
b.Adiabatic
c. Isobaric
d. Equal in all the cases
7.A sample of an ideal gas has volume 2V,Pressure 2P and Temperature T.The mass of the each molecules of the gas is m.The density of the gas is
a. mkT
b. 2P/kt
c. P/kVT
d. 2Pm/kT
8. EN and EH respectivity are the average kinetic energy of the molecules of Nitrogen and Hydrogen.if the two gas are at the same temperature which of the following statement is true?
a. EN > EH
b. EN = EH
c. EN < EH
d. Nothing can be said
9. One mole of a diatomic gas is taken through the process PTn=C where n and C are constant.if the heat capacity of the gas is negative,then the value of n may be
a. 4
b. 3
c. -4
d. -3
10.Certail Ideal gas is found to be obey PV3/2=C during an adiabatic process.If such a gas at intial temperature T is adaiabatically compressed to half the intial volume.Its final temperature will be
a. T√2
b. 2T
c. 2T√2
d. 4T
Solutions
a,3pv
b,2pv
c,pv
d,none of the above
2.An ideal gas was taken from state a to state b in three ways...If W1,W2,W3 are workdone by the gas in patch abc,adc and ac respectively.Which one of the following is true
a. W1 > W2 > W3
b. W1 > W3 > W2
c. W3 > W2 > W1
d. None of the above
3. An ideal gas is taken through the cycle aba.calculate the work done by the gas
a 2pv-1/2πv2
b 2pv+1/2πv2
c 2pv
d None of the above
4. N rods of equal length L and equal crossestion area having thermal conductivities from k to nk respectivity are joined together to form rod of length NL.What is the ratio of Thermal conductivity of whole rod to the thermal conductivity of Nth Rod.
a.1/2(n+1)
b.n+1
c.n
d.1
5.The speed of the four molecules are v,2v,3v,4v.What is the rms speed of the gas
a.v√7
b. 7v
c.v√2
d.v√7.5
6.A sample of gas expands from volume V1 to V2.The amount of workdone by the gas is greatest when the expansion is
a. Isothermal
b.Adiabatic
c. Isobaric
d. Equal in all the cases
7.A sample of an ideal gas has volume 2V,Pressure 2P and Temperature T.The mass of the each molecules of the gas is m.The density of the gas is
a. mkT
b. 2P/kt
c. P/kVT
d. 2Pm/kT
8. EN and EH respectivity are the average kinetic energy of the molecules of Nitrogen and Hydrogen.if the two gas are at the same temperature which of the following statement is true?
a. EN > EH
b. EN = EH
c. EN < EH
d. Nothing can be said
9. One mole of a diatomic gas is taken through the process PTn=C where n and C are constant.if the heat capacity of the gas is negative,then the value of n may be
a. 4
b. 3
c. -4
d. -3
10.Certail Ideal gas is found to be obey PV3/2=C during an adiabatic process.If such a gas at intial temperature T is adaiabatically compressed to half the intial volume.Its final temperature will be
a. T√2
b. 2T
c. 2T√2
d. 4T
Solutions
Monday, 4 February 2008
Objective Thermodynamics question for IITJEE
1. In a given process on an ideal gas,dW>0 and dQ=0 .Then for the gas
a) Temperature will decrease
b) Temperature will increase
c) volume will decrease
d) none of above
2.A cylinder of diameter D and of thermal conductivity k is surrounded by a cylinderical shell of inner diameter D and Outer Diameter 2D made of material of thermal conductivity 2k.The effective thermal conductivity of the system is
a) 5k/3
b) 4k
c) 5k/4
d) 7k/4
3.what all is true for a adiabatic process
a) dQ=0
b) dW=-nCvdT
c) TVy-1=constant
d) all the above three
4. what is the ratio of r.m.s speed of H2 to O2
a) 4:1
b) 1:4
c) 2:1
d) 1:2
5.The coefficent of linear expansion of an inhomogenous rod changes linearly from α1 to α2 from one end to the other end of the rod.The effective coefficient of linear expansion of the rod is
a α1+α2
b 1/2(α1+α2)
c. √α1α2
d. (α1-α2)
Solutions
a) Temperature will decrease
b) Temperature will increase
c) volume will decrease
d) none of above
2.A cylinder of diameter D and of thermal conductivity k is surrounded by a cylinderical shell of inner diameter D and Outer Diameter 2D made of material of thermal conductivity 2k.The effective thermal conductivity of the system is
a) 5k/3
b) 4k
c) 5k/4
d) 7k/4
3.what all is true for a adiabatic process
a) dQ=0
b) dW=-nCvdT
c) TVy-1=constant
d) all the above three
4. what is the ratio of r.m.s speed of H2 to O2
a) 4:1
b) 1:4
c) 2:1
d) 1:2
5.The coefficent of linear expansion of an inhomogenous rod changes linearly from α1 to α2 from one end to the other end of the rod.The effective coefficient of linear expansion of the rod is
a α1+α2
b 1/2(α1+α2)
c. √α1α2
d. (α1-α2)
Solutions
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