Ms

Question 1

Investigate shape and direction of magnetic field

Answer 1

Use a compass to show shape by placing compass around magnet
Move compass in new position and mark direction again
Link directions together to find field line pattern
Use a plotting compass to show direction, points to South Pole

Question 2

Why does a car have greater acceleration without the caravan on it

Answer 2

Mass and acceleration are inversely proportional f=ma
Total mass is less so less air resistance and friction
Less work/ energy used in relation to amount of fuel

Question 3

Half life definition

Answer 3

Time for half of radioactive atoms to decay and radioactivity to half

Question 4

Products of fission

Answer 4

Daughter nuclei
Three neutrons
Gamma radiation

Question 5

Purpose of the moderator (2)

Answer 5

Slows down/ reduces energy of neutrons to increase rate of fission
Increases absorption of neutrons by nuclei

Question 6

What happens if control rod is removed (3)

Answer 6

Rate of reaction increases
Fewer neutrons are absorbed out of the reactor by control rod so more neutrons collide with uranium
Temperature increases

Question 7

Problems on surrounding area due to a nuclear accident (7)

Answer 7

Harmful to nature/ danger to life
High activity levels
Long half life’s difficult for workers to access area/ need protective clothing
Special handling equipment
Distance from hazard zone
Radioactive material mixes with local environment such as soil water air
Distant already due to wind or water

Question 8

Reasons why water flow stops in that thing

Answer 8

Flow when pressure difference, ends when pressure is equal
Pressure causes force on water (P=f/a)
Pressure acts in all directions

Question 9

How to find age of rock using radioactivity (5)

Answer 9

There is a known reactivity when rocks are formed
Measure the proportion of uranium of activity now
Compare activity now to original activity
Determine the number of half lives elapsed
Calculate age from reference of half life

Question 10

How are earth wires a safety feature (5)

Answer 10

Earth wire is connected to casing
If casing becomes live/ live wire touches casing
Provides a low resistance path
Large surge of current in earth wire
Fuse breaks causing current to stop

Question 11

How do electric motors spin (5)

Answer 11

Current in coil causes magnetic field around wires of coil
This field cuts permanent magnet field
Force on the wire
Flemings left and rule
Force up on one side force down on the other

Question 12

Why is shielding in a nuclear reactor necessary (3)

Answer 12

Waste is radioactive
Radiation ionises cells
Radiation is very penetrating

Question 13

Explain an increase in resistance (3)

Answer 13

Lamp heats up
Greater chance of electron collisions
Resistance increases

Question 14

Difference between transverse and longitudinal waves

Answer 14

Longitudinal vibrations are parallel to the direction of transfer

Transverse vibrations are perpendicular to direction of transfer

Question 15

How are fuses protecting

Answer 15

Fuse is in the live wire
When current gets too high due to a fault
Fuse breaks the circuit by melting

Question 16

Why is it not good for a too low fuse

Answer 16

Unable to use appliance as it won’t work since current is too low

Question 17

Reasons for anomalies for car down a ramp experiment

Answer 17

Pushed at different strengths
Different reaction times
More the car moves the more friction

Question 18

Measuring background radiation

Answer 18

Geiger muller detector
Remove radioactive substance
Repeat for different times of the day

Question 19

Why would less 🐟 particles reach the detector during a fire (2)

Answer 19

🐟 are absorbed/ deflected/ scattered

🐟 affected/ blocked by smoke

Question 20

How is there pressure inside a tyre

Answer 20

Continuous random movement of molecules collide with the walls of the tyre
A force is produced by the bombarding of molecules so a pressure/ force is exerted on an area

Question 21

How do you find accurate results for finding resistance

Answer 21

Use a thermometer and a water bath/ allow wires to cool

V=IR

Repeat and average

Interpolated/ additional points

Linear part of graph and use gradient

Question 22

How to accurately find the refractive index of glass

Answer 22

Use a ray box and vary i to obtain a range of values
N= sinI/sinR
Plot graph for sinI and sinR, calculate gradient
Use a sharp pencil and a ruler

Question 23

Reasons for data logger showing varying voltage of a magnet through a coil

Answer 23

Voltage is induced
Field lines are cut
Current changes when magnet does
Magnets slows down so amplitude decreases

Question 24

Black and white hard drives losing more heat wen black on top

Answer 24

Transfer heat by conduction as they emit IR radiation so emit thermal energy
Black emits and loses more heat than white
Thermal energy flows at equilibrium temperature

Question 25

Explain how radioactivity decreases over time

Answer 25

Activity is due to nucleus decaying overtime so less radioactive nuclei are left
Number of nuclei decaying per second decreases

Question 26

What is meant by the term total internal reflection

Answer 26

Reflection occurs inside the optically more dense medium
All the light is reflected
Incident angle is greater than critical angle

Question 27

What do variable resistors control

Answer 27

Circuit resistance and current