物理 1994 年 DSE、CE 選擇題（第 2 頁）

11.

A ray of light travels in air and strikes a semi-circular glass block at an angle of incidence $42^\circ$ . The critical angle of the glass is $42^\circ$ . Which of the following diagrams best shows the subsequent path(s) of the ray ?

Four ray diagrams A to D on a semi-circular glass block

12.

An equal amount of energy is supplied to each of the following substance. Which one of them has the smallest rise in temperature ?

Substance	Mass / kg	Specific heat capacity / $\mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}$
$P$	1	4200
$Q$	2	2300
$R$	3	2200
$S$	4	900

13.

Two identical set-ups with ice in funnel X (heater connected to power supply) and funnel Y (heater not connected), each with a beaker below

The above apparatus is used to find the specific latent heat of fusion of ice. Which of the following is an essential precaution to ensure an accurate result ?

14.

Which of the following graphs correctly shows the relation between the pressure $P$ and the absolute temperature $T$ of a fixed mass of gas at constant volume ?

Four graphs of P against T: A falling line, B hyperbola-like curve, C rising straight line through the origin with dashed extension, D rising line crossing the P axis

15.

The pressure of a fixed mass of gas at $30^\circ$ C is $3\times10^5$ Pa. What would be its pressure if the volume of the gas is doubled and its temperature is increased to $60^\circ$ C ?

16.

A vibrator generates a stationary wave on a string. The diagram shows the string at an instant of maximum displacement. Which of the following statement is correct ?

Stationary wave on a string between a vibrator and a fixed end, with particles P, Q, R and S marked

17.

Arrange the following electromagnetic waves in ascending order of frequencies.

(1)X-rays

(2)Ultra-violet rays

(3)Radio waves

18.

Which of the following statements concerning infra-red radiation is correct ?

19.

Which of the following is NOT an application of ultrasonics ?

20.

Charged rod near an insulated uncharged metal sphere

An insulated charged metal rod is brought near an insulated uncharged metal sphere as shown in the figure. Which of the following can charge the sphere ?

(1)Touching the sphere momentarily with a finger.

(2)Touching the sphere momentarily with the rod.

(3)Touching the rod momentarily with a finger and then touching the sphere momentarily with the same finger.