physics paper 2 - worst qs

Question 1

explain how the ignition circuit works (6)
when the ignition switich is not yet closed and the starter motor needs to touch for motor to work
talk about the motor switch

Answer 1

1. close ignition switch causing current to pass through the electromagnet
2. iron core of electromagnet is magnetised
3. electromagnet attracts shorter side of iron arm
4. iron arm pushes the starter motor to be in contact with each other
5. starter motor circuit is complete
6. so current flows through the motor

Question 2

state 2 ways in which a force produced by a magnetic field from an electrical current can act in the opposite direction

Answer 2

reverse the polarity by connecting the battery the other way around
or reverse the direction of the magnetic field by reversing the magnet

Question 2

when would no force act on a conductor carrying an electric current in a magnetic field (2 ways)

Answer 2

the conductor is parallel to the magentic field
or lines of magnetic field and path of electricity do not cross

Question 3

3 uses of infared radiation
and 1 danger
and its wavelength (m)

Answer 3

1. for remote controls
2. in intruder alarms be detecting body heat
3. cooking
   causes burns if emitted from high intensity source
   10^ -5

Question 3

what is the em spectrum order

Answer 3

radio
microwave
infared
visible
ultraviolet
x ray
gamma

Question 4

3 uses of x-ray radiation
and 1 danger
and its wavelength (m)

Answer 4

1. sees bones
   ionising so can cause cancer

Question 4

3 uses of gamma radiation
and 1 danger
and its wavelength (m)

Answer 4

1. food preservation
2. can sterilise equipment
3. medical imagery and therapy
   its extremely penetrating so can cause damage to body cells and tissues
   10 ^-12

Question 5

3 uses of visible radiation
and 1 danger
and its wavelength (m)

Answer 5

1.to see
causes damage to eye
0.5 x 10^-6

Question 6

3 uses of microwave radiation
and 1 danger
and its wavelength (m)

Answer 6

1. warm things up
   can cause burn tissue

Question 7

3 uses of ultraviolet radiation
and 1 danger
and its wavelength (m)

Answer 7

1. energy-efficient lamps
2. sterilises tanning beds
   is ionising so causes skin cancer

Question 7

3 uses of radiowave radiation
and 1 danger
and its wavelength (m)

Answer 7

1. to carry signals for radios and phones
   none
   10^3

Question 8

what kind of images do convex and concave lens produce

Answer 8

convex - real and virtual
concave - only virtual