物理氣體動力論 DSE、CE 選擇題

1.

A column of gas is trapped inside a cylinder. The piston is now pushed slowly causing the gas to be compressed at a constant temperature. Which of the following statements about the gas molecules in the cylinder is/are correct ?

(1)The average speed of the gas molecules increases.

(2)Each gas molecule exerts a greater impact force on the walls of the cylinder in each collision.

(3)The gas molecules collide more frequently with the walls of the cylinder.

2.

Figure (a): mechanical model of a gas with disc, ball bearings and motor-driven vibrating platform; Figure (b): P-V graph with initial state X and points A, B, C and D around it

Figure (a) shows a mechanical model of a gas and Figure (b) shows the $P$ - $V$ relation of a fixed mass of ideal gas at a certain temperature. If the operating voltage of the motor in the model is increased, which of the following denotes a corresponding transition in the $P$ - $V$ graph (point $X$ represents the initial state of the gas) ?

3.

Which of the following can increase the average kinetic energy of the molecules of a fixed mass of gas ?

(1)increasing the volume of the gas at constant pressure

(2)increasing the pressure of the gas at constant volume

(3)increasing the pressure of the gas at constant temperature

4.

Mechanical model of a gas: a cylinder with ball bearings under a disc, on a vibrating platform driven by a motor

The diagram shows a mechanical model of a gas. The ball bearings are set into motion by a motor-driven vibrating platform. Which of the following statements is/are correct if the operating voltage of the motor is increased ?

(1)The disc rises to a higher level.

(2)The average speed of the ball bearings increases.

(3)The average spacing between the ball bearings increases.

5.

The diagram shows a mechanical model of a gas. The weight of the disc and the power of the motor can give a measure of two different properties of the gas. What are these two properties ?

	Weight of the disc	Power of the motor
	Pressure	Volume
	Pressure	Temperature
	Volume	Temperature
	Temperature	Pressure

6.

Which of the following descriptions concerning the gas molecules is correct when a fixed mass of gas is compressed and also heated at the same time ?

	Average spacing between the gas molecules	Average speed of the gas molecules
	remains unchanged	increases
	decreases	increases
	decreases	decreases
	decreases	remains unchanged

7.

A fixed mass of gas is heated at a constant pressure. Which of the following statements is/are correct ?

(1)The average speed of the gas molecules increases.

(2)The average spacing between the gas molecules increases.

(3)The number of gas molecules remains unchanged.

8.

Energy is supplied to a fixed mass of gas which is kept at a constant volume. Which of the following statements is INCORRECT ?

9.

The diagram shows a mechanical model of a gas. Which of the following processes can be used to demonstrate the variation of the pressure with the volume of a fixed mass of gas under constant temperature ?

10.

If the volume of a fixed mass of gas is reduced at constant temperature, the pressure of the gas increases. Which of the following correctly account(s) for the increase in pressure ?

(1)The gas molecules hit the container wall more frequently.

(2)The average spacing between the gas molecules increases.

(3)The average speed of the gas molecules increases.