A container having some gas was kept in a moving train. The temperature of the gas in the container will

A. increase slightly
B. decrease
C. remain the same
D. become infinite

Options

A. increase slightly
B. decrease
C. remain the same
D. become infinite

Answer

To solve the question regarding the temperature of a gas in a container kept in a moving train, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Scenario**: We have a container filled with gas that is placed in a moving train. The movement of the train can affect the gas inside the container.

2. **Kinetic Theory of Gases**: According to the kinetic theory, the temperature of a gas is directly related to the average kinetic energy of its molecules. The formula for the average kinetic energy (KE) of gas molecules is given by:
\[ KE = \frac{3}{2} k T \]
where \( k \) is the Boltzmann constant and \( T \) is the temperature in Kelvin.

3. **Effect of Movement**: When the container is in a moving train, the gas molecules inside the container will also have an additional velocity due to the motion of the train. This means that the overall kinetic energy of the gas molecules increases because they are not only moving due to their thermal energy but also due to the motion of the train.

4. **Increase in Kinetic Energy**: Since the kinetic energy of the gas molecules increases, we can infer that the average kinetic energy of the molecules will increase.

5. **Conclusion on Temperature**: Since the average kinetic energy of the gas molecules is directly proportional to the temperature, an increase in kinetic energy implies an increase in temperature. Therefore, the temperature of the gas in the container will increase slightly.

6. **Final Answer**: The correct option is **A. increase slightly**.