arthham

JEE Advanced 2010 · Thermodynamics

A diatomic ideal gas is compressed adiabatically to 132\frac{1}{32} of its initial volume. If the initial temperature of the gas is Ti(T_{i} (in Kelvin) and the final temperature is aTi,_{i}, the value of a is

Answer: 44

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Written solution

Step 1: Identify the given parameters.

The volume and temperature relations for the adiabatic compression are given.

Vf=132ViV_f = \frac{1}{32}V_i Tf=aTiT_f = aT_i

Step 2: Determine the adiabatic index for a diatomic gas.

A diatomic ideal gas has 55 degrees of freedom.

γ=1+25=75\gamma = 1 + \frac{2}{5} = \frac{7}{5}

Step 3: Apply the adiabatic relation between temperature and volume.

For an adiabatic process, the temperature and volume are related by a constant.

TiViγ−1=TfVfγ−1T_i V_i^{\gamma-1} = T_f V_f^{\gamma-1}

Step 4: Express the ratio of temperatures.

Rearrange the relation to solve for the temperature ratio.

TfTi=(ViVf)γ−1\frac{T_f}{T_i} = \left(\frac{V_i}{V_f}\right)^{\gamma-1}

Step 5: Calculate the value of aa.

Substitute the given values into the ratio.

a=3275−1a = 32^{\frac{7}{5}-1} a=322/5a = 32^{2/5} a=(25)2/5a = (2^5)^{2/5} a=4a = 4

Answer: The value of aa is 44.

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