2021 Paper 2

Question 1

Give a risk assement to spring practical

Answer 1

Spring could break and fly into eyes so wear goggles

Question 2

Give life cycle of a star the same size as sun

Answer 2

Star will expand to become a red giant
Then collapse to become white dwarf
Then cool to become black dwarf

Question 3

Explain why a blue object appears black when veiwed through a red filter

Answer 3

Only red is transmitted from the filter. Red is absorbed by blue object so no light is reflected by blue object

Question 4

Advantage of repeating measurements

Answer 4

It reduces effects of random errors

Question 5

Explain how someone could measure wave speed without calculating wavelength first

Answer 5

Teacher could measure distance travelled by a wave using a metered ruler and measure time taken to travel distance with a timer. Divide distance by time to get speed

Question 6

Describe how the force on the pedal causes a moment about the rear axle

Answer 6

Force on the pedal causes a moment about the pedal axle which causes a force on the chain causing a moment about the rear axle

Question 7

Explain how a loudspeaker produces a sound wave

Answer 7

Current in coil creates a magnetic field. This interacts with the magnetic field of permanent magnet. This produces a force causing coil to move. When direction of current reverses direction of force reverses producing a sound wave

Question 8

Explain how Flemings left hand rule can be used to predict direction in which rod will move

Answer 8

Hold out left hand
Hold thumb, first finger and second finger at right angles
Second finger represents current wich is pointing out of paper. First finger represents field which is pointing downwards. Thumb points in motion / direction of force wich is pointing right so the rod moves right

Question 9

Suggest 2 changes that would increase the force on copper rod

Answer 9

Decrease resistance of variable resistor ( to increase current?)
Use a stronger magnet