物理 1993 年 DSE、CE 選擇題

1.

Which of the following pairs of physical quantities has/have the same unit ?

(1)Work and potential energy

(2)Power and momentum

(3)Specific heat capacity and specific latent heat of fusion

2.

The paper tape shown is obtained from a trolley moving with uniform acceleration. The frequency of the ticker-tape timer is $50$ Hz. Find the acceleration of the trolley.

Ticker-tape with a first section of 1.5 cm and a later section of 3.6 cm, each spanning five intervals

3.

An object is thrown vertically upwards from a point $A$ . It travels to the highest point $B$ and then falls back to $A$ . Neglecting air resistance, which of the following statements is/are true ?

(1)The total displacement of the object is zero.

(2)The acceleration of the object is constant throughout the motion.

(3)The time for the upward motion is longer than the time for the downward motion.

4.

Force against displacement graph with a shaded rectangular area

The figure shows the variation of the force acting on an object. What physical quantity does the area of the shaded portion represent ?

5.

Acceleration-time graph: constant acceleration until t0, then zero

The above diagram shows the variation of the acceleration of an object which is initially at rest. Which of the following velocity-time graphs correctly describes the motion of the object ?

6.

Pendulum bob released from point P, 0.8 m above its lowest position Q

A pendulum bob is released from rest from a point $P$ $0.8$ m above its lowest position $Q$ , as shown in the diagram. Neglecting air resistance, find the speed of the bob when it reaches $Q$ . (Take $g = 10\ \mathrm{m\,s^{-2}}$ .)

7.

Which of the following phenomena is/are caused by refraction of light ?

(1)A swimming pool appears shallower than it really is.

(2)A metre rule appears bent when dipped in water.

(3)A spectrum is formed when white light passes through a prism.

8.

A lens is used to look at some print on a paper. The image of the word "PHYSICS" is shown above. Which of the following statements is/are correct ?

(1)The lens is a converging lens.

(2)The image lies between the paper and the lens.

(3)The image is real.

The words HKCE PHYSICS EXAM with the word PHYSICS seen through a hand-held lens

9.

The diagram shows a light ray travelling from liquid to air. Find the refractive index of the liquid.

Ray from liquid to air: 30 degrees from the normal in the liquid and 45 degrees in air

10.

Water is used as a coolant in motor car engines because