Physics Mock Exam 2021 Flashcards
Circuit set up needed to investigate how the ______ of a wire affects its resistance.
Circuit needs a battery, switch, ammeter (connected in _______) , voltmeter (connected in ________), ________ clips and a ______ ruler with the _____ wire.
Use CGP too see circuit diagram
length
series, parallel, crocodile clips, metre ruler, test wire
Ammeter measures the _______ (in units called _______) flowing through a component/circuit - it can be put ________ in the ____ circuit, but must be placed in ______ with the _________ (eg ____ wire) - NEVER in ________.
current, ampere/amps, anywhere, main, series, component, test wire, parallel
Voltmeter measures the _______ _______ across the component (e.g. ____ ____) - it must be placed in ________ with the ________ (in this case the test wire) - NOT any other bit of the circuit e.g. the _______
potential difference, test wire, parallel, component, battery/power source
Experiment investigating ______ of wire and _______.
1) Place a ________ clip to the wire level with __ cm on the _____
2) Attach the second _______ clip to the wire some ________ away from the first _____ (e.g. 10cm away)
3) Close the ______, then record the _______ through the _____ and the _____ across it
4) Open the _______, and move the second _______ clip some distance _______ away. Close the _______ again and record the new ______, ______ and ____.
5) ______ this for a number of different ______ of wire between the _____.
length, resistance
crocodile, 0, ruler
crocodile clip, distance, clip
switch, current, wire, p.d.
switch, crocodile clip, further, switch, length, current and p.d.
repeat, lengths, clips
Important equation needed to calculate and use during this experiment
V = _ _ where V = \_\_\_\_\_\_\_ _ = Current _ = \_\_\_\_\_\_\_\_\_
You can _______ this equation to find current and ________ if you have all the measurements needed e.g. R = V/I
V = IR V= Potential Difference (measured in volts V)
I = Current (measured in amps A)
R = Resistance (measured in ohms Ω)
6) Use measurements of ______ and ___ to calculate the _________ for each length of wire - This can be found using R = / (from V = __)
7) Plot a graph of _______ and _____ of wire (Y axis = _______, X axis = _______)
8) You should find that the longer the wire, the _______ the ________.
9) Graph should be a _______ line that goes through the ______ - so resistance is ________ _________ to length
current, p.d., resistance, R=V/I, from V=IR
current, p.d., resistance, R=V/I, from V=IR
resistance, length of wire, Y axis = Resistance X axis = Length of wire
Longer the wire, greater the resistance
Straight line through origin - resistance and length are directly proportional
If the graph doesn’t go through the origin, it could be because the ______ clip wasn’t attached exactly at __ cm at the _____, so all the length readings are slightly ________ - This is a _________ error
You can find the ________ off the graph to ________ resistance for other lengths.
first, 0cm, start, inaccurate, systematic error
gradient, estimate
A series circuit consists of electrical ________ connected one after another in a single ____.
components, loop
In parallel circuits, electrical _______ are connected ________ one another in multiple _____.
component, alongside, loops
Circuit rules for Series circuit
An ______ will pass through every ________ on its way round the circuit. If one of the bulbs/component is broken , then the _______ will not be able to ____ round the circuit. if one bulb goes out, they ____ go out.
electron, component, current, flow, all
Current in series
Current is the ______ anywhere in the circuit as each _____ has to flow through all ________.
I₁ = __ = __
same, charge, components
I₁ = I₂ = I₃
if the resistance of any ________ in a series circuit changes, this will change the value of the _______ in the circuit.
component, current
P.D. in series
P.D. is ______ as ____ done by battery is equal to _____ _____ done on all ________.
Vt = ___ + ___
shared, work, total work, components
Vt = V₁ + V₂
(P.D. across all components = Total/Power supply P.D.)
If the resistance of any ________ in a series circuit changes, this will change the ____ across ___ of the ________.
component, P,D, all, components
Resistance in series
Net (_____) Resistance = The ______ of all resistors _____ together
Adding resistors in series ______ the resistance as ______ only has one ____ to follow, so it must deal with all the _________.
Total, resistance, added
increases, current, path/loop/branch, resistance
Parallel circuit rules
An electron will ____ pass through every ______ on its way round the circuit (due to the _______ branches).
If one of the bulbs/component is broken, then _______ will still ____ round the circuit through the other ____. if one bulb goes out, the other ____ on other _____ will remain ___.
not, component, multiple, current, flow, loop, bulbs, loops, on
Current in parallel
Current is ______ between the multiple ______.
The sum of all the current in all branches is equal to the ______ ______.
If one loop has less resistance than other, it’ll have ____ _______ flowing through it.
It = __ + __
shared, loops/branches
total current
more current
It = I₁ + I₂
If the resistance of any ________ changed in a parallel circuit changes, the value of the _______ in that _____ and the _____ _______ supplied by the battery will _____.
It does not affect the _____ in other _____.
component, current, loop, total current, change
current, loops
P.D. in parallel
The full, total power supply ____ is delivered to each _______.
V1 = ___ = ____ = ____
P,D, branch/loop
V₁ = V₂ = V₃ = Vt
If the resistance of any _______ in a parallel changes, this will have ___ ______ on the ____ across any of the ________.
component, no effect, p,d,, components
Resistors in parallel
The ___ resistance _______ as more components are added, because there are ____ ______ for the ________ to flow through.
1/Rt = ___ + ___
net, decreases, more paths, current
1/R = 1/R₁ + 1/R₂
Check the brightness of bulbs experiment.
Oke
A power supply does ____ on a charge, and so transfers _____ to it.
Charges transfer ______ to a component as they ____ through it, by doing w___ against the ______ of the component.
work, energy
energy, pass, work, against resistance
Work done is simply better known as _____ _______.
energy transferred
The equation to find the work done is as follows.
J=\_\_ \_\_\_\_ done (\_\_\_\_) = \_\_\_\_ (V) + \_\_\_\_\_\_ (C)
J=VQ
Energy transferred (work done) [Joules, J] = P.D. (Volts, V) x Charge (Coulombs, C)
J=VQ can be rearranged to
V=__/__
C=__/__
V=J/Q
C=J/C
Formula triangle for J=VQ
J
V Q
Learn this
A loudspeaker contains a coil of ___ (______) which surrounds one ____ of a permanent _______. The other pole surrounds the ____.
coil of wire (solenoid), pole, magnet, coil
check cgp image
An _______ current flows through the ___ of wire, which is wrapped around the ____ of a c___.
alternating current, coil of wire, base of a cone
The interaction between the ______ fields of the permanent _____ and the _____ forces the coil to move in one _______.
As it’s an _______ current, the current changes ______, forcing the coil back in the other ______.
magnetic fields, magnet, direction
alternating, direction, direction
Electromagnetic induction is the induction of a ___ (and current if there’s a complete _____) across a ______ which is experiencing a change in _______ ______.
P.D, complete circuit, across a conductor, change in magnetic fields
You can think of a p.d. is being induced whenever a _______ ____ line is ____ or crossed by the _________.
If the ____ is part of a complete circuit, it also induces a _______.
magnetic field line, cut or crossed, conductor
coil, current
Two different situations of EM induction
- If the _______ field through an electrical conductor changes (changes ____ or ________).
- If an _______ conductor and a ______ field ____ relative to each other. E.g. moving a ______ in a conductor or moving a ________ in a magnetic field.
magnetic field, shape, reverses
electrical conductor, magnetic field, move, magnet, conductor
- If you move a m____ into a c___, it induces a ___ across the ____ of the ____.
magnet, coil, p.d. ends of the coil
- If you move the m_____ (or c___) in the opposite direction, then the P,D./______ will be ______, Likewise, if you flip the magnet so the other ____ enters the coil, the ____/current will be _______ too.
magnet, coil, current, reversed
pole, P,D, reversed
- If you keep the magnet (or the ___) moving ______ and ______, you produce a p.d. that keeps swapping _______.
coil, backwards and forwards, directions
You can also induct a p.d. by turning a magnet ___ to ___ in a ___ (or turning a coil inside a ______ ____).
end to end, coil, magnetic field
- When you’ve turned the magnet through a half a turn, the direction of the magnetic field ______.
When this happens, the p,d, _____, so the current flows in the _______ direction around the ___ of wire,
reverses
reverses, opposite, coil
- As you turn the magnet, the ______ field through the coil ______. This change in ______ field induces a ___, which can make a ______ flow in the wire.
magnetic, changes, magnetic field, p,d, current
- If you keep turning the magnet in the same direction (e.g. always clockwise), then the p.d will keep on re____ every ____ turn and you’ll get an _______ current.
reversing, half turn, alternating current
Increase p.d. induced by increasing the _____ of the movement, increasing the ______ of the ______ field or having more ____ per ____ length of ___ of wire,
+speed of the movement, +strength of the magnetic field
+more turns per unit length of coil of wire
Current is the flow of electrical _____ around a circuit
It is measured by an _______ and its units is _____ __
charge
