# Aerodynamics Mcqs

Q:

2H₂ + O₂ → 2H₂O is an elementary chemical reaction.

 A) True B) False

Explanation: The reaction between hydrogen and oxygen molecule to form water molecule involves a series of chemical reactions instead of one single step. Thus, it is not an elementary chemical reaction.

76
Q:

Which of these reactions is not carried out for the formation of nitric oxide?

 A) Dissociation reaction of oxygen molecule B) Dissociation reaction of nitrogen molecule C) Shuffle reaction of nitric oxide molecule D) Dissociative – recombination reaction of nitrogen and oxygen

Answer & Explanation Answer: D) Dissociative – recombination reaction of nitrogen and oxygen

Explanation: Not available for this question

56
Q:

In case of translation-vibration transfers, there can be an increase or decrease in kinetic energy.

 A) True B) False

Explanation: When a molecule undergoes a translation-vibration transfer also known as T – V transfer, molecules tend to lose or gain vibrational energy. This energy is reflected in the form of an increase or decrease in the kinetic energy of the molecule undergoing collision.

57
Q:

What does the product of collision frequency and transition probability yield?

 A) Number of transitions per particle per second B) Number of collisions per second C) Number of collisions per second per particle D) Transitions per collision

Answer & Explanation Answer: A) Number of transitions per particle per second

Explanation: The collision frequency (Z) when multiplied with the transition probability (Pi, i + 1) yield the number of transitions per particle per second. Since the collision frequency is the number of collisions taking place per particle and the transition probability gives the number of transitions taking place per collision per particle.

56
Q:

What is the value of transition probability?

 A) 0 B) More than 1 C) Less than 1 D) 1

Explanation: Transition probability is the probability that a molecule will jump to another i + 1 level after the molecular collision. The transition of the molecule moving to a higher energy level requires several number of collisions. This probability value is always less than 1.

58
Q:

For which condition is collision theory low?

 A) Low temperature and pressure B) High temperature and pressure C) Low temperature, high pressure D) High temperature, low pressure

Explanation: Molecular collision frequency is directly proportional to the pressure of the molecule and inversely proportional to the square root of the temperature. Therefore, for obtaining low collision frequency, the pressure should be low and the temperature should be high.

67
Q:

If the temperature increases, what happens to the molecular collision frequency?

 A) Increases B) Decreases C) No change D) First increases then decreases

Explanation: Not available for this question

46
Q:

Time taken for the number of collisions depends on which of these parameters?

 A) Molecular collision frequency B) Molar density C) Number of moles D) Boltzmann constant