ISRO Mechanical & Aerospace 2008 - Question 56

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Topic: Thermodynamics

The specific heat of diatomic gas at constant pressure is given by (R = universal gas constant and M = molecular weight of gas)

  • A. 5/2 R/M
  • B. 5/2 MR
  • C. 7/2 R/M
  • D. 7/2 MR

Answer: C. 7/2 R/M

Explanation: We know that cp = gamma * R_g / (gamma - 1). For diatomic gas, gamma = 1.4. R_g = R/M. cp = 1.4 * (R/M) / (1.4 - 1) = 1.4/0.4 * (R/M) = 7/2 (R/M).

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