97 AL Physics/M.C./P.1
1997 Hong Kong Advanced Level Examination
AL Physics
Multiple Choice Question
97 AL Physics/M.C./P.1
1.
Two wooden blocks A and B are connected by a string which passes over a smooth, fixed pulley as shown. The maximum friction between any two surfaces is 2 N. If a horizontal force F is applied to block B, find its minimum value for moving B.
A.2 N
B.4 N
C.6 N
D.8 N
E.10 N
2.A ball of mass m is projected vertically downwards with speed v from a certain height and rebounds from the ground back to the same height. Which of the following statements is/are correct? (Neglect air resistance.)
(1)The collision between the ball and the ground is not perfectly elastic.
(2)The loss in energy of the ball in the collision is ½mv2.
(3)If the ball is projected vertically upwards from the same height with the same speed, it would rebound to a greater height.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
3.A particle is projected horizontally from a table with an initial speed u and attains a speed v just before hitting the ground. What is the time of flight of the particle? (Neglect air resistance.)
A.
B.
C.
D.
E.It cannot be found as the vertical distance fallen is not known.
4.
The figure shows a car moving round a corner with a radius of 8 m on a banked road of inclination 20º. At what speed would there be no fiction acting on the car along OA?
A.5.0 m/s
B.5.2 m/s
C.5.4 m/s
D.5.6 m/s
E.5.8 m/s
5.
A ball bearing is released from rest at a height h on a smooth track and completes the circular loop of the track. If R is the reaction acting on the ball bearing at the highest point A of the loop, which of the following graphs correctly shows the variation of R with h?
A.
B.
C.
D.
E.
6.A nucleus originally at rest splits into two fragments of unequal mass. The fragment with smaller mass has a larger
(1)momentum.
(2)speed.
(3)kinetic energy.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
7.A constant external torque X is applied to a flywheel which is initially at rest. The angular speed of the flywheel increases to a certain value after 21 s. If the external torque is now doubled, the flywheel will acquire the same angular speed after 9 s. Find the average frictional torque exerted at the bearings of the flywheel.
A.
B.
C.
D.
E.
8.A 50-g mass suspended from a light helical spring oscillates with vertical simple harmonic motion of amplitude 2.5 cm. If the maximum kinetic energy of the mass is 3.0 10-3 J, its frequency of oscillation is
A.0.4 Hz
B.0.8 Hz
C.1.1 Hz
D.1.9 Hz
E.2.2 Hz
9.When a body performs a simple harmonic motion, which of the following is/are correct?
(1)Displacement from the equilibrium position is /2 out of phase with the velocity.
(2)Acceleration is /2 out of phase with the velocity.
(3)Displacement from the equilibrium position is in phase with the acceleration.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
10.A low-altitude satellite near the earth’s surface has a speed of 7.90 km/s. The radius of the earth is about 4 times that of the moon and the ratio of the average density of the earth to that of the moon is about 5 : 4. The speed of a low-altitude satellite near the moon’s surface would be
A.1.77 km/s
B.2.21 km/s
C.2.47 km/s
D.3.57 km/s
E.4.42 km/s
11.
The above figure shows a transverse wave propagating to the right along a string. At the moment shown, which of the labelled particles has its velocity and acceleration in opposite directions?
A.P
B.Q
C.R
D.S
E.T
12.
Three identical long spiral springs are connected respectively to a wall, a light thread and a heavy spring. If a crest-shaped pulse is sent along each spiral spring towards the respective boundary, which of the following diagrams correctly show(s) the reflected pulse? (Transmitted pulse is not shown.)
(1)
(2)
(3)
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
13.A beam of monochromatic light passes through three media of refractive indexes n1, n2 and n3 respectively as shown. The boundaries between the media are parallel.
Which of the following relations between n1, n2 and n3 is correct?
A.n1n3n2
B.n3n1n2
C.n1n2n3
D.n2n1n3
E.n3n2n1
14.A moving ship sounds a foghorn and an echo is received from a cliff behind it. Which of the following wave characteristics of the original sound is/are different from that of the echo?
(1)frequency
(2)amplitude
(3)speed
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
15.
In a Young’s double-slit experiment, light of wavelength 400 nm is used. If the path difference between the light from the two slits X and Y to a point P on the screen is 3000 nm, which of the following is/are correct?
(1)P is the 7th dark fringe.
(2)The fringe separation on the screen increases if the light source is moved closer to the slits.
(3)P becomes a bright fringe if light of wavelength 500 nm is used.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
16.Two pipes A and B, with pipe A closed at one end and pipe B open at both ends, are sounded to give fundamental notes of the same frequency. The length ratio of pipe A to pipe B is
A.1 : 4
B.1 : 2
C.1 : 1
D.2 : 1
E.4 : 1
17.In an arrangement for viewing Newton’s rings, which of the following would be observed if water is introduced to the space between the lens and the glass plate?
A.The rings disappear.
B.The central spot becomes bright.
C.The separation between the rings increases.
D.The rings shift towards the centre.
E.There is no observable change.
18.
The above diagram shows two light rays from a point source O passing in turn through a convex lens L1 and a concave lens L2. Which of the following is true of the focal lengths of the lenses?
Focal length of L1Focal length of L2
A.5 cmless than 10 cm
B.10 cmless than 10 cm
C.10 cm10 cm
D.5 cmgreater than 10 cm
E.10 cm greater than 10 cm
19.A plane transmission grating is placed at the centre of a circular 0º - 360º protractor. A beam of monochromatic light is incident normally on the grating. The zeroth-order maximum occurs at a scale reading of 90º and a first-order maximum occurs at a scale reading of 65º. At what scale reading would a second-order maximum be observed?
A.148º
B.140º
C.130º
D.58º
E.40º
20.The diagram below shows the stress-strain graphs up to the breaking point for two cylindrical rods made from materials P and Q respectively, which have the same diameter and original length.
Which of the two materials
(1)is the more ductile
(2)exhibits greater stiffness
(3)has the greater strength?
(1)(2)(3)
A.QPQ
B.PQP
C.QPP
D.PPQ
E.QQP
21.Which of the following quantities can be increased by increasing the voltage across a metal wire?
(1)the average drift velocity of the conduction electrons
(2)the number of conduction electrons per unit volume
(3)the speed of the electrical signal
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
22.A metal sphere is charged to a potential of 100 V. If the charge density on its surface is 6.0 10-9 Cm-2, find the radius of the sphere.
(Given: permittivity of free space = 8.85 10-12 Fm-1)
A.0.04 m
B.0.15 m
C.0.21 m
D.0.35 m
E.0.60 m
23.
The above figure shows a small coil, connected to a light beam galvanometer, placed in a region of uniform magnetic field between the poles of a magnet. The plane of the coil is parallel to the pole faces. Which of the following actions would produce a deflection of the galvanometer?
(1)Moving the coil to and fro between the poles.
(2)Moving the coil away from the region between the pole faces.
(3)Rotating the coil about a diameter through an angle of 180º.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
24.A variable capacitor can be used
(1)as the volume control of an amplifier.
(2)to tune a radio to receive a certain channel.
(3)to change the power factor of an a.c. circuit.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
25.Two cylindrical metal rods, X and Y, are made from the same material and have the same mass. The length of X is three times that of Y. If currents of 1 A and 2 A pass through X and Y respectively, the ratio of the power dissipation in X to that in Y is
A.9 : 1
B.1 : 4
C.9 : 2
D.3 : 4
E.9 : 4
26.A d.c. motor is connected to a source of constant voltage V. When rotating at a steady speed, the motor draws a current I and the back e.m.f. developed in its armature coil is . Which of the following statements is/are correct?
(1)The resistance of the armature coil is V/I.
(2)The mechanical power developed is I.
(3)The back e.m.f. increases with the speed of rotation.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
27.Which of the following combinations of physical quantities take(s) the unit of time?
(1)capacitance times resistance
(2)inductance divided by resistance
(3)capacitance times inductance
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
28.A charged particle is accelerated across the gap between two parallel metal plates maintained at a certain potential difference in a vacuum. Assuming there is no gravitational force, the energy acquired by the charged particle in crossing the gap depends on
(1)the mass of the charged particles.
(2)the width of the gap.
(3)the potential difference between the plates.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
29.
A cell of e.m.f. 1.5 V is connected in series with a variable resistor of resistance R and an ammeter A of resistance 0.5 . By varying R, a series of ammeter readings, I, are taken and a graph of against R is plotted. The value of the y-intercept is found to be 0.88 A-1. What is the internal resistance of the cell?
A.0.59
B.0.82
C.1.14
D.1.20
E.1.32
30.
In the above circuit, the cell has an e.m.f. 6 V and negligible internal resistance. The resistances of the four resistors R1, R2, R3 and R4 are 6 , 3 , 1 and 2 respectively. The capacitor has capacitance 20 F. At steady state, the charge on the capacitor plate connecting to A is
A.+40 C
B.+80 C
C.0 C
D.-80 C
E.-40 C
31.
A light rectangular wire frame ABCD moves with a uniform speed to the left across a region of uniform magnetic field acting into paper. Which of the following is/are true at the instant shown in the figure?
(1)A current is flowing in the clockwise direction.
(2)The electric potential at B is higher than that at C.
(3)The side AD experiences a magnetic force acting to the right.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
32.A circuit is required for doubling the amplitude of a sinusoidal alternating voltage. Which of the following circuits might be suitable?
(1)
(2)
(3)
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
33.Only a small fraction of the electrical energy supplied to a light bulb is converted into light energy. Which of the following explanations is/are correct?
(1)Energy is absorbed by the glass wall of the bulb.
(2)The resistance of the filament of the bulb is very high.
(3)Most of the energy is emitted as infra-red radiation.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
34.In a horizontal pipeline of cross-sectional area 2.5 10-3 m2, the static pressure and total pressure at a certain point are 0.6 104 Pa and 1.0 104 Pa respectively. The fluid flowing through it is incompressible, non-viscous and has a density of 1.2 103 kgm-3. The volume flow rate in the pipeline is
A.3.2 10-3 m3s-1
B.6.5 10-3 m3s-1
C.7.9 10-3 m3s-1
D.1.0 10-2 m3s-1
E.1.7 10-2 m3s-1
35.Two different ideal gases, A and B, are contained in two identical vessels. If the ratio of their absolute temperature and the ratio of the root-mean-square speed of the molecules are respectively 2 : 1 and 3 : 1, the ratio of their molecular mass is
A.2 : 3
B.2 : 9
C.1 : 6
D.9 : 2
E.3 : 2
36.A fixed mass of an ideal gas undergoes a cycle ABCD in which its pressure p and volume V change as shown in the p-V diagram below.
Which of the following statements is/are correct?
(1)From A to B, work is done by the gas.
(2)From B to C, heat is extracted from the gas.
(3)From C to D, the internal energy of the gas increases.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
37.When a gas is below its critical temperature, which of the following is/are correct?
(1)Intermolecular forces are significant.
(2)The gas can be liquefied by applying pressure alone.
(3)Collisions between molecules are not perfectly elastic.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
38.The instantaneous value of an alternating current I (in A) at time t (in s) is given by the equation
Which of the following descriptions is/are correct?
(1)The a.c. frequency is 50 Hz.
(2)The value of the current varies between A and A.
(3)The r.m.s. value of the current is 2 A.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
39.
A d.c. source is applied to a photocell as shown. Monochromatic radiation is incident on cathode C so that photoelectrons are emitted from the cathode surface. The maximum kinetic energy of the photoelectrons reaching anode A can be increased by using
(1)a d.c. source of higher voltage.
(2)monochromatic radiation of longer wavelength.
(3)the same monochromatic radiation but higher of intensity.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
40.
In the above circuit, a signal generator of fixed output voltage is connected in series with a resistor R and a capacitor C. When the frequency of the signal generator is gradually increased, which of the following is the correct variation of the ammeter and voltmeter readings?
Ammeter readingVoltmeter reading
A.increases increases
throughoutthroughout
B.increases decreases
throughoutthroughout
C.increases increases and
throughoutthen decreases
D.increases and decreases
then decreasesthroughout
E.increases and decreases and
then decreasesthen increases
41.The transition of electrons between three energy levels in a particular atom gives rise to three spectral lines. The shortest and longest wavelengths of those spectral lines are 1 and 2 respectively. The wavelength of the other spectral line is
A.
B.
C.
D.
E.
42.
In the above operational amplifier circuit, the output voltage Vout is
A.-5 V
B.-2.5 V
C.0 V
D.+2.5 V
E.+5 V
43.is one of the nuclides in the uranium decay series. If the stable end-product of this series is , the number of -particles emitted between the stage and the end of the series is
A.4
B.6
C.10
D.14
E.20
44.Which of the following statements about a typical nuclear reactor in a power plant is/are correct?
(1)The percentage of 235U isotope in fuel rods is higher than that in natural uranium.
(2)Boron-coated steel rods are used to control the rate of neutron production.
(3)Pressurized water is used as coolant inside the reactor core.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
45.In an experiment to determine the period of oscillation, T, of a simple pendulum, the time, t, for a number of complete oscillations is taken. It is found that the time for 30 complete oscillations is 28.7 0.3 s. Which of the following statements is/are correct?
(1)The reading error in t can be reduced by counting 50 oscillations.
(2)The percentage error in T is the same as that in t.
(3)The period T determined should be quoted as 0.96 0.01 s.
A.(1) only
B.(3) only
C.(1) and (2) only
D.(2) and (3) only
E.(1), (2) and (3)
Question No.Key
1.C
2.C
3.D
4.C
5.E
6.D
7.E
8.E
9.C
10.A
11.E
12.D
13.B
14.C
15.B
16.B
17.D
18.D
19.A
20.A
21.A
22.B
23.D
24.D
25.E
Question No.Key
26.D
27.C
28.B
29.B
30.E
31.A
32.C
33.B
34.B
35.B
36.C
37.C
38.D
39.A
40.B
41.D
42.A
43.A
44.E
45.D