物理 1993 年 DSE、CE 選擇題（第 2 頁）

11.

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

12.

An energy of $16500$ J is supplied to a metal block of mass $0.5$ kg and its rise in temperature is $64^\circ\mathrm{C}$ . The specific heat capacity of the metal is

13.

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. 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 ?

14.

The absolute temperature of a fixed mass of gas is $T$ . If the pressure and volume of the gas are both doubled, its absolute temperature becomes

15.

Vibrator generating a wave on a string travelling to the right, with points P and Q marked

A vibrator generates a travelling wave on a string. The above diagram shows the shape of the string at a certain instant. Which of the following shows the shape of the string between $P$ and $Q$ after a quarter of a period ?

Four possible shapes of the string between P and Q, A to D

16.

Plane water waves travelling upwards towards a straight barrier PQ inclined to the waves

Plane water waves travel towards a straight barrier $PQ$ as shown in the figure above. Which of the following diagrams best shows the reflected waves ?

17.

A radio station broadcasts at a frequency of $94$ MHz. Find the wavelength of the radio waves.

18.

Two vibrators P and Q in a ripple tank, N the midpoint of PQ and M on the perpendicular bisector MN

Two vibrators $P$ and $Q$ are set to vibrate in phase in a ripple tank. $MN$ is the perpendicular bisector of $PQ$ as shown above. Which of the following statements is/are true ?

(1)Constructive interference occurs along

MN

.

(2)Destructive interference occurs along

PQ

.

(3)A crest is always formed at

M

.

19.

Which of the following statements is/are true ?

(1)Light is a transverse wave.

(2)Light does not undergo diffraction.

(3)Light transmits energy.

20.

The frequencies of two musical notes $X$ and $Y$ are $256$ Hz and $512$ Hz respectively. If $X$ and $Y$ both have the same amplitude, which of the following statements is/are true ?

(1)

Y

has a higher pitch than

X

.

(2)The loudness of

X

is larger than that of

Y

.

(3)The wavelength of

Y

is longer than that of

X

.