Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Science > P5 > Flashcards

P5 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

How are objects attracted to eachother after object is rubbed against one’s hair or other suface?

A

It is attracted as during the process of rubbing in gain or losses electrons, which make it positvely or negatively charged

An example of this is rubbing a baloon against your hair and then seeing how it is able to stick to walls, as it is attracted to them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is one model for an electric circuit?

A

+ photo

  • hear the mouse represents the battery
  • and the are charge - through the movement of the mouse
  • the paddle wheel causes resistance, causing energy to be used in the circuit.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What way does conventional current and which way does the electrons flow?

A
  • covential current flows clockwise in a closed circuit from + to -
  • electrons flow anticlockwise in a closed circuit from - to +
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an electric current and how is it measured?

A
  • electric current is the flow of charge around a closed circuit
  • greater current, more energy it can transfers
  • an anmeter is used to measure the current
  • slows the amount of charge going through the meter every second
  • how it is connected in a circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What fact remains constant about electric current in a series circuit?

A

the speed remains constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some more facts about current?

A
  • the current is not used up when it flows around the circuit
  • the charge is used up and transfered
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name two types of circuits?

A
  • a parallel circuit
  • a series circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What causes resistance?

A
  • lamps
  • resistors
  • wire a little bit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do wire get hot when current flows through them?

A
  • charges in the metal= electrons
  • ion collide with the lattice structure of the wire
  • cause energy to be transferred
  • some metals have wider lattice structures which craetes less resistance for the ions or charges traveling through the wire
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is resistance measured in a series and parallel circuit?

A

-series circuit

R1+R2= R3

-Parallel circuit

R3=1 divided by 1 over R1+ 1 over R2+1 over Rn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What determines the size of the current?

A
  • the voltage of the battery
  • the resistance of the circuit compoents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is a voltmeter connected in a circuit, and what happens when more voltage goes through a lamp?

A
  • connect across the compoent
  • more voltage= brighter the lamp
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is voltage?

A
  • the voltage is the push of the current around the circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is resistance?

A
  • this is a force that means more energy is required to push the current
  • the resistance effects the size of the current?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the formula for the resistance of a conductor?

A

resistance of a conductor= photo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a fact about current and voltage?

A
  • current in circuit is proportional to the voltage of the battery
  • this is known as ohm’s law

resistance= the voltage divide by current

17
Q

What is a variable resistor?

A
  • its resistance can be changed or varied by moving a slider or dial
  • more coils of wire the current has to go through, the greater the resistance
18
Q

What bis an light dependent resistor?

A
  • the more light it is exposed tp the greater the resistance
19
Q

What is a thermistor?

A
  • increases resistance according to to temperature
  • lower ressitance - hotter
20
Q

What is potentail difference?

A
  • higher potentail energy at the begining
  • lowest potential energy after the last compoent
21
Q

What does a voltmeter measure ?

A
  • the potentail difference between two points e.g.

A to B

22
Q

How do you measure the power of a circuit and work done?

A
23
Q

What is the link between magnetism and electricity?

A
  • when there is an electric current there is a magnetic field in the region of the wire
  • winding the wire round in a coil

it strengthens the magnetic force

  • each turn of the wire has its own magnetic field, which is added together
24
Q

What is an electromagnet?

A
  • a wire coil around an iron core with a current running through it
  • can be switched on and off
25
Q

How does an electric motor work?

A
  • a permenant magnet(compass needle) experiences a force if placed in a magnetic field

+photo

  • no forces at the two ends of the coil
  • yet is aforce on the two sides of the coil
  • forces will be at right angles to both the magnetic field and the current
  • one force is up
  • other is down
  • cause turning effect
  • coil is made with several turns of wir
  • stronger the turning force

+photo

  • in a electric motor
  • once the coil has turned 90 degrees, the direction of the current is reversed
  • makes the turning continuous
26
Q

Hoe is the current of an electric motor reversed in direction?

A
  • by using a split ring commutor- pair of rings and brushes
  • no fixed wires in motors
  • half the ring rubs against the brush for half a turn
  • changes direction of the current
27
Q

How does a generator work?

A
  • this is done by moving a magnet near to a coil of wire
  • current only, when the magent is moving
28
Q

What is an electromagnetic induction?

A

=photo

  • this occurs when the magnet is removed from inside the coil
  • there is a smaal current in the opposite direction to the original current
29
Q

How did Faraday believe a generator to work?

A
  • no movement - no voltage
  • magnet- moving - the magnetic field is changing
  • magnetic field lines arew cutting the coil
  • causes potential difference or voltage across the coil
  • in a complete circuit , voltage causes a current
  • magnet + coil behaves like a battery
  • when athe magnet is removed from the coil
  • the field changes
  • causes induced voltage in the opposite direction of the current
30
Q

What is a. c. and d. c.

A

alternating current produced by generator

  • current goes in two directions positive negative on a graph
  • changing magnetic field
  • direct current
  • from a battery and travels in one direction
31
Q

How can the size of alternating voltage produced by a generator be incraesed?

A
  • stronger rotating magnet or electromegnet
  • rotating it faster
  • using a fixed coil with more turns
  • putting an iron core inside the fixed coil
  • strength of the magnetic field is in increased
32
Q

How can the size of induced voltage be increased?

A
  • moving the magnet in and out more quickly
  • stronger magnet
  • using a coil with more turns
33
Q

How does a transformer work?

A
  • changed the current in the primary coil induces the voltage in the secondary coil
  • output of the transformer depends on the number of coil of wire
  • more in secondary then primary
  • step up transformer
  • voltage increases
  • yet current in the secondary coil will be less
  • no greater power supplied

P=IV

34
Q

What is the formula for the output of a tranformer?

A
35
Q

What was fleming left hand rule?

A

Science (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions