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PHYSICS 0625/04Paper 4 Theory (Extended) For examination from 2023MARK SCHEME

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Gen

eric

Mar

king

Prin

cipl

es

Thes

e ge

nera

l mar

king

prin

cipl

es m

ust b

e ap

plie

d by

all

exam

iner

s w

hen

mar

king

can

dida

te a

nsw

ers.

The

y sh

ould

be

appl

ied

alon

gsid

e th

e sp

ecifi

c co

nten

t of t

he m

ark

sche

me

or g

ener

ic le

vel d

escr

ipto

rs fo

r a q

uest

ion.

Eac

h qu

estio

n pa

per a

nd m

ark

sche

me

will

als

o co

mpl

y w

ith th

ese

mar

king

pr

inci

ples

.

GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

1:

Mar

ks m

ust b

e aw

arde

d in

line

with

:

•th

e sp

ecifi

c co

nten

t of t

he m

ark

sche

me

or th

e ge

neric

leve

l des

crip

tors

for t

he q

uest

ion

•th

e sp

ecifi

c sk

ills

defin

ed in

the

mar

k sc

hem

e or

in th

e ge

neric

leve

l des

crip

tors

for t

he q

uest

ion

•th

e st

anda

rd o

f res

pons

e re

quire

d by

a c

andi

date

as

exem

plifi

ed b

y th

e st

anda

rdis

atio

n sc

ripts

.

GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

2:

Mar

ks a

war

ded

are

alw

ays

who

le m

arks

(not

hal

f mar

ks, o

r oth

er fr

actio

ns).

GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

3:

Mar

ks m

ust b

e aw

arde

d po

sitiv

ely:

•m

arks

are

aw

arde

d fo

r cor

rect

/val

id a

nsw

ers,

as

defin

ed in

the

mar

k sc

hem

e. H

owev

er, c

redi

t is

give

n fo

r val

id a

nsw

ers

whi

ch g

o be

yond

the

scop

e of

the

sylla

bus

and

mar

k sc

hem

e, re

ferr

ing

to y

our T

eam

Lea

der a

s ap

prop

riate

•m

arks

are

aw

arde

d w

hen

cand

idat

es c

lear

ly d

emon

stra

te w

hat t

hey

know

and

can

do

•m

arks

are

not

ded

ucte

d fo

r err

ors

•m

arks

are

not

ded

ucte

d fo

r om

issi

ons

•an

swer

s sh

ould

onl

y be

judg

ed o

n th

e qu

ality

of s

pelli

ng, p

unct

uatio

n an

d gr

amm

ar w

hen

thes

e fe

atur

es a

re s

peci

fical

ly a

sses

sed

by th

e qu

estio

n as

indi

cate

d by

the

mar

k sc

hem

e. T

he m

eani

ng, h

owev

er, s

houl

d be

una

mbi

guou

s.

GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

4:

Rul

es m

ust b

e ap

plie

d co

nsis

tent

ly, e

.g. i

n si

tuat

ions

whe

re c

andi

date

s ha

ve n

ot fo

llow

ed in

stru

ctio

ns o

r in

the

appl

icat

ion

of g

ener

ic le

vel

desc

ripto

rs.

GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

5:

Mar

ks s

houl

d be

aw

arde

d us

ing

the

full

rang

e of

mar

ks d

efin

ed in

the

mar

k sc

hem

e fo

r the

que

stio

n (h

owev

er; t

he u

se o

f the

full

mar

k ra

nge

may

be

lim

ited

acco

rdin

g to

the

qual

ity o

f the

can

dida

te re

spon

ses

seen

).

0625

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GE

NE

RIC

MA

RK

ING

PR

INC

IPLE

6:

Mar

ks a

war

ded

are

base

d so

lely

on

the

requ

irem

ents

as

defin

ed in

the

mar

k sc

hem

e. M

arks

sho

uld

not b

e aw

arde

d w

ith g

rade

thre

shol

ds o

r gra

de

desc

ripto

rs in

min

d.

Scie

nce-

Spec

ific

Mar

king

Prin

cipl

es

1 E

xam

iner

s sh

ould

con

side

r the

con

text

and

sci

entif

ic u

se o

f any

key

wor

ds w

hen

awar

ding

mar

ks. A

lthou

gh k

eyw

ords

may

be

pres

ent,

mar

ks

shou

ld n

ot b

e aw

arde

d if

the

keyw

ords

are

use

d in

corr

ectly

.

2 Th

e ex

amin

er s

houl

d no

t cho

ose

betw

een

cont

radi

ctor

y st

atem

ents

giv

en in

the

sam

e qu

estio

n pa

rt, a

nd c

redi

t sho

uld

not b

e aw

arde

d fo

r any

co

rrec

t sta

tem

ent t

hat i

s co

ntra

dict

ed w

ithin

the

sam

e qu

estio

n pa

rt. W

rong

sci

ence

that

is ir

rele

vant

to th

e qu

estio

n sh

ould

be

igno

red.

3 A

lthou

gh s

pelli

ngs

do n

ot h

ave

to b

e co

rrec

t, sp

ellin

gs o

f syl

labu

s te

rms

mus

t allo

w fo

r cle

ar a

nd u

nam

bigu

ous

sepa

ratio

n fro

m o

ther

syl

labu

s te

rms

with

whi

ch th

ey m

ay b

e co

nfus

ed (e

.g. e

than

e / e

then

e, g

luca

gon 

/ gly

coge

n, re

fract

ion 

/ ref

lect

ion)

.

4 Th

e er

ror c

arrie

d fo

rwar

d (e

cf) p

rinci

ple

shou

ld b

e ap

plie

d, w

here

app

ropr

iate

. If a

n in

corr

ect a

nsw

er is

sub

sequ

ently

use

d in

a s

cien

tific

ally

co

rrec

t way

, the

can

dida

te s

houl

d be

aw

arde

d th

ese

subs

eque

nt m

arki

ng p

oint

s. F

urth

er g

uida

nce

will

be

incl

uded

in th

e m

ark

sche

me

whe

re

nece

ssar

y an

d an

y ex

cept

ions

to th

is g

ener

al p

rinci

ple

will

be

note

d.

5 ‘L

ist r

ule’

gui

danc

e

Fo

r que

stio

ns th

at re

quire

n re

spon

ses

(e.g

. Sta

te tw

o re

ason

s …

):

•Th

e re

spon

se s

houl

d be

read

as

cont

inuo

us p

rose

, eve

n w

hen

num

bere

d an

swer

spa

ces

are

prov

ided

. •

Any

resp

onse

mar

ked

igno

re in

the

mar

k sc

hem

e sh

ould

not

cou

nt to

war

ds n

. •

Inco

rrec

t res

pons

es s

houl

d no

t be

awar

ded

cred

it bu

t will

stil

l cou

nt to

war

ds n

. •

Rea

d th

e en

tire

resp

onse

to c

heck

for a

ny re

spon

ses

that

con

tradi

ct th

ose

that

wou

ld o

ther

wis

e be

cre

dite

d. C

redi

t sho

uld

not b

e aw

arde

d fo

r any

resp

onse

s th

at a

re c

ontra

dict

ed w

ithin

the

rest

of t

he re

spon

se. W

here

two

resp

onse

s co

ntra

dict

one

ano

ther

, thi

s sh

ould

be

trea

ted

as a

sin

gle

inco

rrec

t res

pons

e. •

Non

-con

tradi

ctor

y re

spon

ses

afte

r the

firs

t n re

spon

ses

may

be

igno

red

even

if th

ey in

clud

e in

corr

ect s

cien

ce.

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6 C

alcu

latio

n sp

ecifi

c gu

idan

ce

C

orre

ct a

nsw

ers

to c

alcu

latio

ns s

houl

d be

giv

en fu

ll cr

edit

even

if th

ere

is n

o w

orki

ng o

r inc

orre

ct w

orki

ng, u

nles

s th

e qu

estio

n st

ates

‘sho

w

your

wor

king

’.

Fo

r que

stio

ns in

whi

ch th

e nu

mbe

r of s

igni

fican

t fig

ures

requ

ired

is n

ot s

tate

d, c

redi

t sho

uld

be a

war

ded

for c

orre

ct a

nsw

ers

whe

n ro

unde

d by

th

e ex

amin

er to

the

num

ber o

f sig

nific

ant f

igur

es g

iven

in th

e m

ark

sche

me.

Thi

s m

ay n

ot a

pply

to m

easu

red

valu

es.

Fo

r ans

wer

s gi

ven

in s

tand

ard

form

(e.g

. a ×

10n ) i

n w

hich

the

conv

entio

n of

rest

rictin

g th

e va

lue

of th

e co

effic

ient

(a) t

o a

valu

e be

twee

n 1

and

10 is

not

follo

wed

, cre

dit m

ay s

till b

e aw

arde

d if

the

answ

er c

an b

e co

nver

ted

to th

e an

swer

giv

en in

the

mar

k sc

hem

e.

U

nles

s a

sepa

rate

mar

k is

giv

en fo

r a u

nit,

a m

issi

ng o

r inc

orre

ct u

nit w

ill n

orm

ally

mea

n th

at th

e fin

al c

alcu

latio

n m

ark

is n

ot a

war

ded.

E

xcep

tions

to th

is g

ener

al p

rinci

ple

will

be

note

d in

the

mar

k sc

hem

e.

7 G

uida

nce

for c

hem

ical

equ

atio

ns

M

ultip

les 

/ fra

ctio

ns o

f coe

ffici

ents

use

d in

che

mic

al e

quat

ions

are

acc

epta

ble

unle

ss s

tate

d ot

herw

ise

in th

e m

ark

sche

me.

S

tate

sym

bols

giv

en in

an

equa

tion

shou

ld b

e ig

nore

d un

less

ask

ed fo

r in

the

ques

tion

or s

tate

d ot

herw

ise

in th

e m

ark

sche

me.

Mar

k ca

tego

ries

B m

arks

Thes

e ar

e in

depe

nden

t mar

ks, w

hich

do

not d

epen

d on

oth

er m

arks

. For

a B

mar

k to

be

awar

ded,

the

poin

t to

whi

ch it

refe

rs m

ust b

e se

en s

peci

fical

ly in

the

cand

idat

e’s

answ

er.

M m

arks

Thes

e ar

e m

etho

d m

arks

upo

n w

hich

A m

arks

late

r dep

end.

For

an

M m

ark

to b

e aw

arde

d, th

e po

int t

o w

hich

it re

fers

mus

t be

seen

sp

ecifi

cally

in th

e ca

ndid

ate’

s an

swer

. If a

can

dida

te is

not

aw

arde

d an

M m

ark,

the

late

r A m

ark

cann

ot b

e aw

arde

d ei

ther

.

C m

arks

Thes

e ar

e co

mpe

nsat

ory

mar

ks w

hich

can

be

awar

ded

even

if th

e po

ints

to w

hich

they

refe

r are

not

writ

ten

dow

n by

the

cand

idat

e,

prov

idin

g su

bseq

uent

wor

king

giv

es e

vide

nce

that

they

mus

t hav

e kn

own

them

. For

exa

mpl

e, if

an

equa

tion

carr

ies

a C

mar

k an

d th

e ca

ndid

ate

does

not

writ

e do

wn

the

actu

al e

quat

ion

but d

oes

corr

ect w

orki

ng w

hich

sho

ws

the

cand

idat

e kn

ew th

e eq

uatio

n, th

en th

e C

m

ark

is a

war

ded.

If a

corr

ect a

nsw

er is

giv

en to

a n

umer

ical

que

stio

n, a

ll of

the

prec

edin

g C

mar

ks a

re a

war

ded

auto

mat

ical

ly. It

is o

nly

nece

ssar

y to

co

nsid

er e

ach

of th

e C

mar

ks in

turn

whe

n th

e nu

mer

ical

ans

wer

is n

ot c

orre

ct.

A m

arks

Thes

e ar

e an

swer

mar

ks. T

hey

may

dep

end

on a

n M

mar

k or

allo

w a

C m

ark

to b

e aw

arde

d by

impl

icat

ion.

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Abb

revi

atio

ns a

nd g

uida

nce

/A

ltern

ativ

e an

swer

s fo

r the

sam

e m

arki

ng p

oint

.

unde

rline

Act

ual w

ord

unde

rline

d m

ust b

e us

ed b

y ca

ndid

ate

(gra

mm

atic

al v

aria

nts

acce

pted

).

(bra

cket

s)Th

e w

ord

or p

hras

e in

bra

cket

s is

not

requ

ired

but s

ets

the

cont

ext.

AND / a

ndS

tate

men

ts o

n bo

th s

ides

of t

he A

ND

are

nee

ded

for t

hat m

ark.

OR / o

rIn

dica

tes

alte

rnat

ive

answ

ers,

any

one

of w

hich

is s

atis

fact

ory

for s

corin

g th

e m

arks

.

NOT / not

Indi

cate

s th

at a

n in

corr

ect a

nsw

er is

not

to b

e di

sreg

arde

d bu

t can

cels

ano

ther

oth

erw

ise

corr

ect a

ltern

ativ

e of

fere

d by

the

cand

idat

e fo

r thi

s m

ark.

Accept / Acc

A le

ss th

an id

eal a

nsw

er w

hich

sho

uld

be m

arke

d co

rrec

t.

Igno

re / Ig

Indi

cate

s th

at s

omet

hing

whi

ch is

not

cor

rect

or i

rrel

evan

t is

to b

e di

sreg

arde

d.

e.c.

f.‘e

rror

car

ried

forw

ard’

o.w

.t.t.e

.‘o

r wor

ds to

that

effe

ct’

s.f.

‘sig

nific

ant f

igur

es’ –

ans

wer

s ar

e no

rmal

ly a

ccep

tabl

e to

any

num

ber o

f sig

nific

ant f

igur

es ⩾

2. A

ny e

xcep

tions

to th

is g

ener

al

rule

will

be

spec

ified

in th

e m

ark

sche

me.

Arit

hmet

ic e

rror

sIf

the

only

err

or in

arr

ivin

g at

a fi

nal a

nsw

er is

cle

arly

an

arith

met

ic o

ne, a

ll bu

t the

fina

l A m

ark

can

be a

war

ded.

Reg

ard

a po

wer

of t

en e

rror

as

an a

rithm

etic

err

or.

Tran

scrip

tion

erro

rsIf

the

only

err

or in

arr

ivin

g at

a fi

nal a

nsw

er is

bec

ause

giv

en o

r pre

viou

sly

calc

ulat

ed d

ata

has

clea

rly b

een

mis

read

but

use

d co

rrec

tly, a

ll bu

t the

fina

l A m

ark

can

be a

war

ded.

Frac

tions

Onl

y ac

cept

thes

e w

here

spe

cifie

d in

the

mar

k sc

hem

e.

Cro

ssed

-out

wor

kW

ork

whi

ch h

as b

een

cros

sed

out a

nd n

ot re

plac

ed b

ut c

an e

asily

be

read

, sho

uld

be m

arke

d as

if it

had

not

bee

n cr

osse

d ou

t.

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fro

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Pag

e 6

of 1

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202

0

Que

stio

nA

nsw

erM

arks

1(a)

men

tion

of g

radi

ent o

f gra

ph a

t t =

30 

s O

R ta

ngen

t dra

wn

at t

= 30

 s a

nd tr

iang

le d

raw

n O

R v

alue

s of

t an

d v

take

n fro

m

grap

hC

1

α =

tvD D

OR

cal

cula

tion

show

n

C1

acce

lera

tion

in ra

nge

0.30

to 0

.45 

m / 

s2A

1

1(b)

acce

lera

tion

less

 / at

a s

low

er ra

teB

1

less

driv

ing

forc

e O

R g

reat

er re

sist

ive

forc

e / f

rictio

n / a

ir re

sist

ance

 / dr

ag A

ND

resu

ltant

forc

e le

ssB

1

1(c)

area

und

er g

raph

 / ar

ea u

nder

line

C1

dist

ance

= (2

0 ×

40) +

(21

× 4

0 ×

10) O

R 21

× (3

0 +

20) ×

40

C1

1000

 mA

1

Que

stio

nA

nsw

erM

arks

2(a)

forc

eB

1

impu

lse

B1

2(b)

(i)(p

=) m

v O

R 0

.046

× 6

5C

1

3.0 

kg m

 / s

OR

3.0

 N s

A1

2(b)

(ii)

(F =

) (

)t

mvu

− o

r ..

000050

30

OR

a = (

)t

vu

− a

nd F

= m

a or

.. 000050

0046

65#

or

0.04

6 ×

130 

000

C1

6000

 NO

R60

00 N

A1

2(b)

(iii)

elas

tic (e

nerg

y) O

R s

train

(ene

rgy)

B1

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

023

Pag

e 7

of 1

2©

UC

LES

202

0

Que

stio

nA

nsw

erM

arks

3(a)

(i)nu

clea

r fus

ion

B1

3(a)

(ii)

nucl

ei c

ombi

ne / 

join

toge

ther

B1

smal

l nuc

lei t

o la

rger

nuc

lei O

R h

ydro

gen

to h

eliu

m (i

n so

me

way

) OR

loss

of m

ass

B1

3(b)

any

suita

ble

reso

urce

, e.g

. fos

sil f

uels

; hyd

roel

ectri

c; w

ave;

win

d N

OT

geot

herm

al, n

ucle

arM

1

rene

wab

le O

R n

ot (a

ccor

ding

ans

wer

) AN

D m

atch

ing

expl

anat

ion

A1

3(c)

any

two

adva

ntag

es fr

om: n

o po

llutin

g ga

ses 

/ qui

et / 

low

mai

nten

ance

 / ca

n be

pla

ced

on ro

ofs 

/ cle

an / 

chea

p to

run

B2

any

two

disa

dvan

tage

s fro

m: i

nter

mitt

ent s

uppl

y / u

nattr

activ

e / t

akes

up

spac

e / u

ses

land

 / d.c

. out

put

B2

Que

stio

nA

nsw

erM

arks

4(a)

atom

s co

llide

with

wal

l (an

d re

boun

d) O

R a

tom

s re

boun

d fro

m w

all

B1

(ato

ms)

und

ergo

cha

nge

of m

omen

tum

C1

forc

e on

wal

l = (t

otal

) rat

e of

cha

nge

of m

omen

tum

(of a

tom

s)O

R =

cha

nge

of m

omen

tum

(of a

tom

s) p

er s

econ

dO

R =

cha

nge

of m

omen

tum

(of a

tom

s) /

time

A1

4(b)

(i)fe

wer

ato

ms

per u

nit v

olum

e O

R d

ensi

ty o

f gas

less

B1

rate

of c

ollis

ion

(with

wal

ls o

f bal

loon

) dec

reas

es O

R fe

wer

col

lisio

ns p

er u

nit a

rea

B1

4(b)

(ii)

PV

= c

onst

ant O

R P

1V1

= P

2V2

OR

(P2

=) VPV 2

11 O

R .

.12

10

1096

5#

#C

1

8.0 ×

104  P

aA

1

Que

stio

nA

nsw

erM

arks

5(a)

arra

ngem

ent:

Ice:

in la

ttice

 / re

gula

r / a

rran

ged 

/ ord

erly

 / fix

ed in

pla

ceW

ater

: ran

dom

 / irr

egul

ar / 

not a

rran

ged 

/ not

ord

erly

mot

ion:

Ice:

vib

rate

Wat

er: m

ove

(aro

und)

or s

lide

over

eac

h ot

her

B2

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

020

Pag

e 8

of 1

2©

UC

LES

202

0

Que

stio

nA

nsw

erM

arks

5(b)

(i)d

= Vm

in a

ny fo

rm O

R (m

=) V

d O

R 1

800 ×

0.02

5 ×

920

C1

41 0

00 k

gA

1

5(b)

(ii)

(∆E

=) c

m∆θ

OR

2.1

× 1

03 × 4

1 00

0 ×

3.5

C1

3.0 ×

108  (J

) A

1

Que

stio

nA

nsw

erM

arks

6(a)

(i)an

y tw

o ra

ys th

at s

tart

at th

e to

p of

the

imag

e fro

m:

•se

ems

to c

ome

from

F1

to le

ns a

nd e

mer

ges

para

xial

ly •

pass

es th

roug

h ce

ntre

of l

ens

unde

viat

ed •

para

xial

to th

e le

ns a

nd p

asse

s th

roug

h F 2

M2

two

corr

ect r

ays

trace

d ba

ck a

nd im

age

indi

cate

dA

1

6(a)

(ii)

any

two

of: e

nlar

ged 

/ inv

erte

d / r

eal u

nder

lined

B1

enla

rged

AN

D in

verte

d A

ND

real

und

erlin

edB

1

6(b)

refra

cted

ray

in p

rism

bel

ow y

ello

w ra

y A

ND

abo

ve n

orm

alB

1

emer

gent

ray

dive

rgin

g aw

ay fr

om th

e ye

llow

ray

AN

D o

utsi

de o

f pris

mB

1

Que

stio

nA

nsw

erM

arks

7(a)

330–

350 

m / 

sB

1

7(b)

v =

fλ O

R (f

=)

v m O

R .()a

0022

C1

Cor

rect

ans

wer

: e.g

. 330

m /

s gi

ves

15 0

00 H

zA

1

7(c)

use

of tr

ansd

ucer

to s

end

and

rece

ive

puls

es o

f ultr

asou

ndB

1

(dis

play

use

d to

det

erm

ine)

tim

e fo

r ech

o of

pul

se to

retu

rn fr

om fr

ont A

ND

bac

k of

bub

ble

B1

use

of s

peed

of s

ound

in th

e m

etal

B1

use

of d

ista

nce

= sp

eed ×

time

to c

alcu

late

pos

ition

and

siz

eB

1

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

023

Pag

e 9

of 1

2©

UC

LES

202

0

Que

stio

nA

nsw

erM

arks

8(a)

RS =

RA +

RB in

any

form

OR

(RS =

) RA +

RB O

R (R

S =

) 4 +

8C

1

(RS =

) 12 

(Ω)

C1

(RP =

) 1

11

RR

SC

+b

l in a

ny fo

rm

OR

(RP =

) (

)R

RR

R

SC

SC

+

OR

(RP =

)

12161

1 +d

n OR

(RP =

) (

)186

12#

C1

(RP =

) 4.0

 ΩA

1

8(b)

V8

= su

pply

V ×

128 dn O

R =

24 × 128 dn

C1

(V8

=) 1

6 V

A1

OR

alte

rnat

ive

rout

e

I 8 =

V12

supply

OR

= 1224

OR

= 2

 (A)

C1

(V8

= 2 ×

8 =)

16 

VA

1

Que

stio

nA

nsw

erM

arks

9(a)

ball

gets

–ve

cha

rge

(from

–ve

pla

te)

B1

–ve(

ly c

harg

ed b

all)

attra

cted

to +

ve /

repe

lled

from

–ve

B1

9(b)

parti

cles

: ele

ctro

nsB

1

dire

ctio

n: fr

om le

ft to

righ

t (th

roug

h am

met

er)

B1

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

020

Pag

e 10

of 1

2©

UC

LES

202

0

Que

stio

nA

nsw

erM

arks

9(c)

Q =

It i

n an

y fo

rm O

R tQ

wor

ds, n

umbe

rs, s

ymbo

lsC

1

corr

ect u

se o

f f =

4 H

z O

R T

= 0

.25 

s i.e

. 8.5

× 1

0–10 ×

4 O

R

..025

85

1010

#-

C1

(I =

) 3.4

× 1

0–9 A

A1

Que

stio

nA

nsw

erM

arks

10(a

)(i)

Np

93237

B1

24 aB

1

10(a

)(ii)

gam

ma

and

beta

will

not

pro

duce

eno

ugh

ions

 / io

n pa

irs p

er c

mB

1

10(b

)(N

o of

Am

ato

ms

rem

aini

ng =

8 ×

1014

– 6

× 1

014) =

2 ×

1014

C1

4 ×

1014

(Am

ato

ms

rem

ain

afte

r 470

yrs

or 1

hal

f-life

)C

1

(2 ×

1014

Am

ato

ms

rem

ain

afte

r) 9

40 y

rs o

r 2 h

alf-l

ives

A1

Que

stio

nA

nsw

erM

arks

11(a

)hy

drog

en g

as in

ste

llar c

loud

 / ne

bula

pul

led

toge

ther

by

grav

ityB

1

tem

pera

ture

of h

ydro

gen

incr

ease

s A

ND

a p

roto

star

is fo

rmed

B1

nucl

ear f

usio

n be

gins

and

out

war

d fo

rce

from

this

reac

tion

bala

nces

inw

ard

forc

e of

gra

vity

B1

11(b

)an

y th

ree

from

:m

icro

wav

e ra

diat

ion

is o

bser

ved

at a

ll po

ints

in s

pace

aro

und

the

Ear

th o

.w.t.

t.e.

radi

atio

n w

as p

rodu

ced

whe

n th

e U

nive

rse

was

form

edth

is ra

diat

ion

has

expa

nded

into

the

mic

row

ave

regi

on o

f the

ele

ctro

mag

netic

spe

ctru

mth

is is

evi

denc

e th

at th

e U

nive

rse

expa

nded

B3

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

023

Pag

e 11

of 1

2©

UC

LES

202

0

Que

stio

nA

nsw

erM

arks

12(a

)NN

VV

ps

ps=

in a

ny fo

rm O

R (N

s =)

VN

V

p

ps

#

OR

240

8000

6#

C1

200

A1

12(b

)I pV

p =

I sVs i

n an

y fo

rm O

R (I

p =)

IV

V p

ss

# O

R . 240

20

6#

C1

0.05

0 A

A1

0625

/04

Cam

brid

ge IG

CS

E –

Mar

k S

chem

e Fo

r exa

min

atio

n

SPEC

IMEN

fro

m 2

020

Pag

e 12

of 1

2©

UC

LES

202

0

BLA

NK

PA

GE