Corrections Flashcards
When investigating affects of light on an LDR with a lamp where must the experiment be conducted and why
- in a darkened room
- so no ambient light affects the LDR
How can you measure the volume of an irregular shape lighter than water (3)
- submerge it with a sinker
- measure the total volume displaced by object and submerging object
- subtract the volume displaced by sinker alone
explain in terms of particles why solids have greater densities than water
- more closely packed particles
- more mass per unit volume
voltage of sockets in a ring main
230 V
advantages of a ring main (5)
- cables can be made thinner
- each part of the cable carries less current
- sockets can be placed anywhere
- each socket has 230V applied
- sockets can be operated separately
In the change of state from solid to liquid what does breaking of bonds allow particles to do
slide past one another
In the change of state from liquid to gas what does the breaking of bonds allow particle to do
allows them to escape from one another
purpose of the iron core in a transformer (2)
- links the alternating magnetic field from the primary to secondary coil
- strengthens the magnetic field
what type of line of best fit is drawn on a current - voltage graph for a resistor
straight line
Describe a test to test if a component is a diode (3)
- connect in series one way and see if the current is high
- reverse the cell
- see if the current is zero (a diode only lets current flow one way)
Why does a satellite in geostationary orbit above the equator appear to stay in a fixed place above the Earth (2)
- satellite orbits in the same time
- that it takes the Earth to spin once
what is the Earth wire
takes current away from an appliance when a fault occurs for protection
explain in terms of particles how heat conducts through copper (4)
- the particles vibrate faster
- they collide with neighbours, transferring heat energy
- copper also has free electrons that move faster
- electrons pass on the energy as they move through the lattice
explain why the liquid in the heated solar panel circulates (4)
- heated liquid is less dense
- heated liquid rises
- colder liquid falls
- convection current form
how does a generator make electricity in a power plant (3)
- fuel is burned to heat water
- kinetic energy of steam turns a turbine
- turbine turns generator producing electricity