Specimen Paper

Question 1

Why is the ruler straight when measuring spring extension? (2)

Answer 1

To reduce the error when measuring extension

As the ruler at an angle would make the measurement extension shorter

Question 2

One technique to improve accuracy of measuring spring extension? (2)

Answer 2

Use a pointer at the bottom of the spring

So that the pointer goes across the ruler

Question 3

Extension vs weight graph when line curves (2)

What and why

Answer 3

Spring has been inelastically deformed

Reached the limit of proportionality

Question 4

Weakness of balloon model for galaxy expansion (1)

Answer 4

There is a limit to how far the balloon can expand

Question 5

Suggest why a theory about the universe could be wrong (1)

Answer 5

New evidence

Question 6

Object slit 1cm

Explain why the image height in centimetres was the same as the magnification (2)

Answer 6

magnification = image height/ object height

dividing by an object height of 1 cm gives the same (numerical) value

Question 7

How to improve ray box experiment at greater distances to still get accurate values? (1)

Answer 7

Use taller object

Question 8

Explain how the ignition circuit works. (4) marks
Basically a switch with electromagnet
Image question 4.2

Answer 8

closing the (ignition) switch causes a current to pass through the electromagnet
 the iron core (of the electromagnet) becomes magnetised
 the electromagnet/iron core attracts the (short side of the )
iron arm
 the iron arm pushes the contacts (inside the electromagnetic switch) together
 the starter motor circuit is complete
 a current flows through the starter motor

Question 9

State the reason why light is refracted as it crosses from air into glass. (1)

Answer 9

velocity/ speed of the light decreases

Question 10

Just two reasons why scientist decided to publish their results

Answer 10

To allow peer review of the data

To promote further enquiry

Question 11

Difference between systematic and random error

Answer 11

Systematic - causes by students ( usually out by the same each time)
Random - caused by humans

Question 12

Difference between distance and displacement

Answer 12

Distance is scalar

Displacement is a vector

Question 13

There are places on the journey where the train accelerates without changing speed
Explain how this can happen (2)

Answer 13

The train changes direction to the velocity changes

Acceleration is the rate of change of velocity

Question 14

If the sledges pulled an angle to the surface the value calculator for the constant of the friction would not be appropriate
explain why (2 marks)

Answer 14

Only a (the horizontal) component of the force would be pulling the sled forward
the vertical component of the force (effectively) lifts the sled reducing the force of the surface on the sled

Question 15

Explain why atmospheric pressure decreases with increasing altitude (3)

Answer 15

Air molecules colliding with a surface create pressure
at increasing altitude fewer molecules
so always less weight of air than below

Question 16

Explain how loudspeaker converts current into soundwaves

Answer 16

the current in the electrical circuit is varying
the current passes through the coil
the coil experiences a force (inwards or outwards)
reversing the current reverses the force
the size of the current affects the size of the force
the varying current causes the coil to vibrate
the (vibrating) coil causes the cone to vibrate
the vibrating cone causes the air molecules to move
the movement of the air molecules produces the pressure variations in the air needed for a sound wave
the air molecules bunch together forming compressions and spread apart forming rarefactions