SATHEE: Thermodynamics Question 128

Thermodynamics Question 128

Question: The specific heat of hydrogen gas at constant pressure is $C_{P} = 3.4 \times 10^{3} c a l / k g^{o} C$ and at constant volume is $C_{V} = 2.4 \times 10^{3} c a l / k g^{o} C .$ If one kilogram hydrogen gas is heated from $10^{o} C$ to $20^{o} C$ at constant pressure, the external work done on the gas to maintain it at constant pressure is

[MP PMT 1995; DPMT 2001]

Options:

A) $10^{5}$ cal

B) $10^{4}$ cal

C) $10^{3}$ cal

D) $5 \times 10^{3}$ cal

Show Answer

Answer:

Correct Answer: B

Solution:

From FLOT DQ = DU + DW Work done at constant pressure ${(Δ W)}_{P} = {(Δ Q)}_{P} - Δ U$

${(Δ Q)}_{P} - {(Δ Q)}_{V}$

(As we know ${(Δ Q)}_{V} = Δ U$ )

Also ${(Δ Q)}_{P} = m c_{P} Δ T$

and ${(Δ Q)}_{V} = m c_{V} Δ T$

Therefore ${(Δ W)}_{P} = m (c_{P} - c_{V}) Δ T$

Therefore ${(Δ W)}_{P} = 1 \times (3.4 \times 10^{3} - 2.4 \times 10^{3}) \times 10 = 10^{4} c a l$

Thermodynamics Question 128

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Answer:

Solution:

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Thermodynamics Question 128

Question: The specific heat of hydrogen gas at constant pressure is CP=3.4×103cal/kgoC and at constant volume is CV=2.4×103cal/kgoC. If one kilogram hydrogen gas is heated from 10oC to 20oC at constant pressure, the external work done on the gas to maintain it at constant pressure is

Options:

Answer:

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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