Physics Thermodynamics
Get insights from 156 questions on Physics Thermodynamics, answered by students, alumni, and experts. You may also ask and answer any question you like about Physics Thermodynamics
- 156
Questions
- 0
Discussions
- 0
Active Users
- 1
Followers
Have a question about Physics Thermodynamics? Ask our experts
Keep it short & simple. Type complete word. Avoid abusive language.
An ideal gas undergoes four different processes from the same initial state as shown in the figure below: Those process are adiabatic, isothermal, isobaric and isochoric. The cure which represents the adiabatic process among 1, 2, 3 and 4 is:
An ideal gas undergoes four different processes from the same initial state as shown in the figure below: Those process are adiabatic, isothermal, isobaric and isochoric. The cure which represents the adiabatic process among 1, 2, 3 and 4 is:
Adiabatic curve is more steeper than isothermal.
Upvote 
A Carnot engine has an efficiency of when its source is at a temperature . The temperature of the sink is:
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
A Carnot engine has an efficiency of when its source is at a temperature . The temperature of the sink is:
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
As increased by 3 times
So
- (c) Fundamental harmonic frequency open pipe
(say)
Fundamental harmonic frequency of closed pipe
(say)
Upvote An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is S? and that of the other part is S?. Given that S? > S?. If the piston is removed then the total entropy of the system will be :
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is S? and that of the other part is S?. Given that S? > S?. If the piston is removed then the total entropy of the system will be :
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
Kindly go through the answers
S? × S?
Upvote For an adiabatic expansion of an ideal gas, the fractional change in its pressure is equal to ( where γ is the ratio of specific heats):
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
For an adiabatic expansion of an ideal gas, the fractional change in its pressure is equal to ( where γ is the ratio of specific heats):
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
PV? = C ⇒ V? (dP/dV) + P (γV^ (γ-1) = 0 ⇒ dP/dV = -γ (P/V) ⇒ dP/P = -γ (dV/V)
Upvote Which one is the correct option for the two different thermodynamic processes?
<!-- [if !supportLineBreakNewLine]--><!--[endif]-->
Which one is the correct option for the two different thermodynamic processes?
<!-- [if !supportLineBreakNewLine]--><!--[endif]-->
Pressure decreases with an increase in volume in both isothermal and adiabatic processes. In an adiabatic process, as volume decreases, pressure increases with the increase in temperature.
Upvote If one mole of the polyatomic gas is having two vibrational modes and β is the ratio of molar specific heats for polyatomic gas (β = C_p / C_v), then the value of β is:
If one mole of the polyatomic gas is having two vibrational modes and β is the ratio of molar specific heats for polyatomic gas (β = C_p / C_v), then the value of β is:
In an LCR series AC circuit, the phase difference φ between current and voltage is: φ = tan? ¹ (X? - X? ) / R)
If each vibrational mode contributes two degrees of freedom and the total degrees of freedom f = 3 + 3 + 4 = 10, then:
β = 1 + 2/f = 1 + 2/10 = 1.2
Upvote The P-V diagram of a diatomic ideal gas system going under cyclic process as shown in figure. The work done during an adiabatic process CD is (use γ = 1.4):
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
The P-V diagram of a diatomic ideal gas system going under cyclic process as shown in figure. The work done during an adiabatic process CD is (use γ = 1.4):
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
For adiabatic process CD,
W = (P? V? - P? V? ) / (γ - 1) = (100 × 4 - 200 × 3) / (1.4 - 1) = -500J
Upvote Two ideal polyatomic gases at temperatures T₁ and T₂ are mixed so that there is no loss of energy. If F₁ and F₂, m₁ and m₂, n₁ and n₂ be the degrees of freedom, masses, number of molecules of the first and second gas respectively, the temperature of mixture of these two gases is:
Two ideal polyatomic gases at temperatures T₁ and T₂ are mixed so that there is no loss of energy. If F₁ and F₂, m₁ and m₂, n₁ and n₂ be the degrees of freedom, masses, number of molecules of the first and second gas respectively, the temperature of mixture of these two gases is:
U = U? + U? = (n? /N_A) (F? R/2)T? + (n? /N_A) (F? R/2)T?
For the mixture: U = (n? +n? )/N_A * (FR/2)T
F = (n? F? + n? F? ) / (n? + n? )
Equating the expressions for U and solving for T gives:
T = (n? F? T? + n? F? T? ) / (n? F? + n? F? )
Upvote A Carnot's engine working between 400 K and 800 K has a work output of 1200J per cycle. The amount of heat energy supplied to the engine from the source in each cycle is:
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
A Carnot's engine working between 400 K and 800 K has a work output of 1200J per cycle. The amount of heat energy supplied to the engine from the source in each cycle is:
<!-- [if !supportLineBreakNewLine]-->
<!--[endif]-->
η = 1 - T_C / T_H
η = 1 - 400/800 = 1 - ½ = ½
η = W/Q_H ⇒ ½ = W/Q_H ⇒ Q_H = 2W = 2 × 1200 = 2400 J
Upvote A polyatomic ideal gas has 24 vibrational modes. What is the value of γ ?
A polyatomic ideal gas has 24 vibrational modes. What is the value of γ ?
f = f_Translational + f_Rotational + f_Vibrational
f = 3 + 3 + 48 = 54 (Since each vibrational mode has two degrees of freedom)
γ = 1 + 2/f = 1 + 2/54 = 1 + 1/27 = 28/27 ≈ 1.03
Upvote