physics

1. what is the best way of describing a physical quantity?
a aquantity with a magnitude and a direction but no unit
ba quantity with a magnitude and a unit
c a quantity with a magnitude but no direction
da quantity with a unit but no magnitude

2 which pair includes a vector quantity and a scalar quantity?
a displacement and acceleration
b_ force and kinetic energy
c power and speed
d_ work and potential energy

3 a force f acts at an angle @to the horizontal.
f
ra
scares honzontal
what are the horizontal and the vertical components of the force?
horizontal vertical
component component
a fcosé f cos (90° — 0)
b fcos@ f sin (90° — 6)
cc fsing f cosé
d f sing f cos (90° — 6)

4 what will reduce the systematic errors when taking a measurement?
a adjusting the needle on a voltmeter so that it reads zero when there is no potential difference
across it
b measuring the diameter of a wire at different points and taking the average
c_ reducing the parallax effects by using a marker and a mirror when measuring the amplitude
of oscillation of a pendulum
d timing 20 oscillations, rather than a single oscillation, when finding the period of a pendulum

5 in an experiment to determine the young modulus e of the material of a wire, the measurements
taken are shown.
mass hung on end of wire m = 2.300 + 0.002 kg
original length of wire 1= 2.864 + 0.005m
diameter of wire d=0.82 + 0.01mm
extension of wire e=7.6+0.2mm
the young modulus is calculated using
g -4mgl
nd?e
where g is the acceleration of free fall.
the calculated value of e is 1.61 x 10'°°nm”.
how should the calculated value of e and its uncertainty be expressed?
a (1.61 + 0.04) x 10°°nm?
b (1.61 + 0.05) x 10'°°nm~*
c (1.61 + 0.07) x 10° nm?
d (1.61 + 0.09) x 10°°nm~*

6 arock on the surface of mars is projected vertically upwards with an initial speed of 9.4ms"'. the
rock rises to a height of 12m above the surface.
assume there is no atmosphere on mars.
what is the acceleration of free fall near the surface of mars?
a 0.39ms* b 3.7ms* cc 7.4ms* d 9.8ms*

7 two masses, m and m, are connected by an inextensible string which passes over a frictionless
pulley. mass m rests on a frictionless slope, as shown.
rx ,
mp ,
frictionless slope
the slope is at an angle @to the horizontal.
the two masses are initially held stationary and then released. mass m moves down the slope.
which expression must be correct?
a sing< ™ b coso< ™ cc sing> @ d cosg> ™
m m m m

8 a sky-diver falls from a stationary balloon at time t = 0. as the sky-diver falls, her speed and the
air resistance increase until the force of the air resistance is equal to her weight.
which graph best shows the variation with time t of the displacement s for the motion of the
sky-diver?
a b cc d

9 a ball of mass 0.20kg, travelling in the x-direction at a speed of 0.50ms", collides with a ball of
mass 0.30kg travelling in the y-direction at a speed of 0.40ms™.
the two balls stick together after the collision, travelling at an angle @to the x-direction.
i 0.30kg
y0.40ms" x-direction
0.50ms" !

0.20kg ‘ y-direction
what is the value of 0?
a 39° b 40° cc 50° d 51°

10 four cuboids with identical lengths, breadths and heights are immersed in water. the cuboids are

held at the same depth and in identical orientations by vertical rods, as shown.
_—_— ite ee c= ene
— hy fe eee ete

water has density p.

cuboid w is made of material of density 4p.

cuboid x is made of material of density 2.

cuboid y is made of material of density p.

cuboid z is made of material of density 0.5 .

which statement is correct?

a the upthrust of the water on each of the cuboids is the same.

b_ the upthrust of the water on w is twice the upthrust of the water on x.

c_ the upthrust of the water on x is twice the upthrust of the water on w.

d_ the upthrust of the water on y is zero.

12 which diagram shows a couple formed by two forces, each of magnitude f, acting on a rod?
a b f
f f f
cc r d
f f

13  full-fat milk is made up of fat-free milk mixed with fat.
a volume of 1.000 x 10m? of full-fat milk has a mass of 1.035kg. it contains 4.00% fat by
volume.
the density of fat-free milk is 1.040 x 10°kgm~®.
what is the density of fat?
a 1.25 x 10’kgm®
b 9.15 x 10?kgm™®?
c 9.28 x 10?kgm™?
d 1.16 x 10°kgm?

14 gas is trapped inside a cylinder by a piston of cross-sectional area a. the piston is not
frictionless.
p -, q
=,
gas —+—
atmospheric
pressure
—_—
<_—————
s
the gas is heated and this causes it to expand, pushing back the piston through distance r from
position p to position q. the length of the gas column is then s.
which expression represents the amount of work done by the gas against the atmosphere during
this expansion?
a_ (atmospheric pressure) x ar
b_ (atmospheric pressure) x as
c (pressure inside the gas) x ar
d_ (pressure inside the gas) x as

15 water from a reservoir is fed to the turbine of a hydroelectric system at a rate of 510kgs"'. the
reservoir is 280 m above the level of the turbine.
the electrical output from the generator driven by the turbine is a current of 205a at a potential
difference of 5800v.
what is the efficiency of the system?
a 8.3% b 12% c 83% d 85%

16 a ball is thrown vertically up into the air. it rises to the top of its path before beginning to fall
vertically downwards.
q top of path
q midpoint of path
+o starting position
assume that the gravitational potential energy of the ball is zero at its starting position.
which statement about the ball is not correct?
a asit rises, its kinetic energy is transferred to gravitational potential energy.
b at the midpoint of its path, its gravitational potential energy is equal to its initial kinetic
energy.
c_ atthe top of its path, its kinetic energy is zero.
d_ at the top of its path, its total energy is less than its initial total energy.

17 a force of 1000n is needed to lift the hook of a crane at a constant velocity. the crane is then
used to lift a load of mass 1000kg at a constant velocity of 0.50ms™.
what is the power needed to lift the hook and the load?
a 4.9kw b 5.4kw c 20kw d 22kw

18 data for a steel wire on an electric guitar are listed.
diameter = 5.0 x 10m
young modulus = 2.0 x 10''pa
tension = 20n
the wire snaps and contracts elastically. assume the wire obeys hooke’s law.
by what percentage does the length 1 of a piece of the wire contract?
a 13x10%% b 51x107% c 13x10°% d 51x10°%

19 the graph shows how the extension of a spring varies with the force used to stretch it.

4, 0 = essenceeacissenacansnnmmaannaaagy

extension/cm

2.0

fj '

0 10 20 30

force/kn
what is the strain energy in the spring when the extension is 4.0cm?

a 60j b 120j cc 600j d 1200j

20 the displacement-distance graph for a transverse progressive wave is shown.
, xx
displacement
0
(0) distance
| y
the phase difference between points x and y can be expressed as (180 n)°.
what is the value of n?
a 1.5 b 25 c 3.0 d 6.0

21 the four graphs represent a progressive wave on a stretched string. graphs a and b show how
the displacement d varies with distance x along the string at one instant. graphs c and d show
how the displacement d varies with time ¢t at a particular value of x.

the labels on the graphs are intended to show the wavelength 4, the period t and the amplitude
a of the wave, but only one graph is correctly labelled.
which graph is correctly labelled?
a b
e aa
wd---------------- ~~ --------------- im
“viv \ “l\ ln
0 0 :
0 \ / x b \/ x
| —
cc d
a vi
---------------- me a - --- = === == 5 ===
“vin ln “viv ln
0 0
pa ne prs

22 acathode-ray oscilloscope (c.r.o.) is used to determine the frequency of a sound wave.

the diagram shows the waveform on the screen.
in | [al | a | a |
ai pa | an ta
pat a ty ty
litt nt a ut a
cav ow oe
pi fet y | ty |

the time-base setting is 5.0ms/div.

what is the frequency of the sound wave?

a 57hz b 71hz c 114hz d 143hz

23 a police car travels at a velocity of 30.0ms~ directly towards a stationary observer. the horn of
the car emits sound of frequency 2000 hz. the speed of sound is 340ms"'.
what is the frequency of the sound heard by the observer?
a 1840hz b  2000hz c 2180hz d 2190hz

24 a vibrating tuning fork is held over a measuring cylinder, as shown.
& tuning fork
water
water is then gradually poured into the measuring cylinder. a much louder sound is first heard
when the water level is 2.9cm above the base of the measuring cylinder. a second much louder
sound is heard when the water level reaches a height of 67.3cm above the base.
the speed of sound in air is 330ms™.
what is the frequency of the tuning fork?
a 128hz b 256hz c §12hz d 1024hz

25 a water wave in a ripple tank is diffracted as it passes through a gap in a barrier.
which two factors affect the angle of diffraction of the wave?
a_ the amplitude and frequency of the incident wave
b_ the amplitude of the incident wave and the width of the gap
c_ the wavelength and amplitude of the incident wave
d_ the wavelength of the incident wave and the width of the gap

26 a double-slit interference pattern using red light of wavelength 7.0 x 10-’m has a fringe spacing
of 3.5mm.
which fringe spacing would be observed for the same arrangement of apparatus but using blue
light of wavelength 4.5 x 10-’ m?
a 2.3mm b 3.5mm cc 5.4mm d 9.0mm

27 two parallel metal plates are situated 20cm apart in a vacuum. they are connected to two
sources of potential difference as shown.
~— proton | 20cm
+ | +
800v 300v

a proton is released in the space between the plates.
what is the magnitude and direction of the acceleration of the proton?
a 2.4x 10''ms? downwards
b  2.4x 10''ms” upwards
c 5.3.x 10''ms downwards
d 5.3 10''ms~” upwards

28 a particle having mass m and charge +q enters a uniform electric field with speed v.
initially, the particle is travelling at right-angles to the electric field.
during its movement through the field, the particle is deflected through distance d, as shown.
path of particle
anu
region of uniform"
electric field
a eee particle of mass 2m, charge +q and speed v enters the electric field along the same
path.
what is the distance through which this particle is deflected in the electric field?
a a b @ cc 2d d 4d
4 2

29 what is a possible charge on a particle?
a 640x 107°c
b 4.00 x 10-°c
cc 112x10°%c
d 9.11x10°%c

30 a slice of germanium of cross-sectional area 1.0cm* carries a current of 56ua. the number
density of charge carriers in the germanium is 2.0 x 10cm”. each charge carrier has a charge
equal to the charge on an electron.

slice of
area‘'l.ocm? germanium
~~ current |
56 pa
what is the average drift velocity of the charge carriers in the germanium?
a 0.18ms" b 18ms‘ cc 180ms" d 1800ms‘

31 a cell of electromotive force (e.m.f.) e and internal resistance r is connected to an external
resistor of resistance r, as shown.
_&
; r
al
what is the power dissipated in the external resistor?
2 2 2 2
a e*(r+r) b e*r c e*(r+r) d bar
r? (r+ry r? (r+ry

32 the graph shows the i-v characteristic of an electrical component.
ff.
0 v
what is the component?
aa filament lamp
b  ametallic conductor at constant temperature
c_aresistor
d asemiconductor diode
se ee

33 a metal wire of length 1.4m has a uniform cross-sectional area of 7.8 x 10°‘ m’.
the resistivity of the metal is 1.7 x 10°qm.
what is the resistance of the wire?
a 0.016 b 0.0319 c 330 d 640

34 a battery of electromotive force (e.m.f.) 6.0v and negligible internal resistance is connected to
three resistors each of resistance 6.0.q.
which circuit will produce a current through the battery of 0.67 a?
a b
6.0v 6.0v
6.02
6.0q 6.0q 6.0q 6.00
ld
[|
cc d
6.0v 6.0v
6.0q
6.02 600 lt
ch | eon
a
— | 600
lt

35 the diagram shows a network of three resistors. two of these, marked r, are identical. the other
resistor has a resistance of 5.00.
y
r
xx 5.00
r
z
the resistance between y and z is found to be 2.50.
what is the resistance between x and y?
a 0.300 b 0.530 cc 1.90 d 3.30

36 the diagram shows a battery, a fixed resistor, an ammeter and a variable resistor connected in
series.
a voltmeter is connected across the fixed resistor.
the resistance of the variable resistor is reduced.
which row describes the changes in the readings of the ammeter and of the voltmeter?
[| ammeter | votnetr
a decrease decrease
b decrease increase
cc increase decrease
d increase increase

37 the circuit diagram shows a battery of electromotive force (e.m.f.) 9.0v and negligible internal
resistance. it is connected to two resistors of resistances 1609 and r. the output potential
difference vou is 4.0v.

160q
——
90v |
——
r | vout = 4.0v
what is the resistance r?
a 320 b 490 cc 710 d 1280

38 in the circuit shown, xy is a length l of uniform resistance wire. a potential difference is applied
across xy. r; and r; are unknown resistors. j is a sliding contact that joins the junction of r; and
r2 to points on xy through a lamp s.

l
a oe
- x vag gs ¥ +
o o
j
&)s
ry r,
[| [| |
j is moved along xy to a point at which the lamp is off. this point is at a distance x from x.
the potential difference across r, is v; and the potential difference across ro is v2.
: . v4
what is the value of the ratio vv. ?
2
al b x cc l~x dp ~~
x i x l-x

39 a nucleus of magnesium-23 undergoes p* decay, as represented by the nuclear equation shown.
3mg > x + bt + %
what is nucleus x?
a 2na b zai cc na d al

40 which list contains only leptons?
a electron, neutrino, positron
b electron, neutrino, proton
c_ electron, proton, neutron
d neutrino, neutron, positron

Solve 9702_s18_qp_13