1.	any three from:	max 3
X-rays – to obtain shadow pictures of bones
UV – in sunbeds to give a sun tan
IR – in a remote control for a TV
microwaves – to communicate with satellites
[3]

2.		(i)	Speed = wavelength × frequency	3
3.108 = 1.5.106 × wavelength
Wavelength = 200m
for 1 mark each

3.	(a)	(i)	IR/micro/radio	1
for 1 mark
(ii)	UV/X-rays/gamma	1
for 1 mark
6.	(a)	(i)	gamma	1
for 1 mark
(ii)	IR or microwaves	1
for 1 mark
(b)	(i)	to produce shadow pictures of bones / metals	1
teeth inspection
airport security
detection / seeing inside the body
for 1 mark
(ii)	sunbeds/	1
inspection / detection of security markings
cause fluorescence in banknotes / stamps
killing bacteria / insects
for rapid growth /
sewage treatment
discos - if qualified
for 1 mark
(c)	are reflected	1
for 1 mark
	from (electrically charged) layers in the atmosphere so follow Earth’s	2
curvature / in upper atmosphere
for 1 mark
[7]