1What are the two types of charge?
Positive and negative
2What is formed when a body has equal amounts of positive and negative charge?
A neutral body
3How do like charges behave towards each other?
They repel
4How do opposite charges behave towards each other?
They attract
5Why don't insulators conduct charge?
Their charged particles cannot flow and are fixed
6Why can conductors conduct charge?
Their charged particles are delocalised and can flow
7What is transferred when two insulators are rubbed together?
Electrons
8What charge does an object gain when it loses electrons?
Positive charge
9What charge does an object gain when it gains electrons?
Negative charge
10What happens when conductors are rubbed together?
Electrons flow in and out keeping them neutral
11When does sparking occur?
When enough charge builds up between close, non-touching objects
12What is the force experienced between charged objects called?
Electrostatic force
13Is electrostatic force a contact or non-contact force?
Non-contact force
14How does distance affect electrostatic force?
Smaller separation results in greater force
15What force causes a stream of water to bend towards a charged object?
Induced attraction
16In which direction do electric fields point?
Away from positive charges and towards negative charges
17What does a greater charge indicate about electric field lines?
There are more field lines and a stronger force
18What two things are needed for a current to flow?
A closed circuit and a source of potential difference
19What is the formula relating charge, current, and time?
$charge = current \times time$
20How does current behave in a single, closed loop?
It has the same value at any point
21What is potential difference (p.d.) defined as?
Energy transferred per unit charge
22What unit is potential difference measured in?
Volts
23What instrument is used to measure potential difference?
Voltmeter
24How is a voltmeter placed in a circuit?
In parallel across a component
25What is current defined as?
Rate of flow of charge
26What unit is current measured in?
Amps
27What instrument is used to measure current?
Ammeter
28How is an ammeter placed in a circuit?
In series
29What is a series circuit?
A closed circuit where the current only follows a single path
30What is a parallel circuit?
A branched circuit where the current splits into multiple paths
31What is the voltage like across each branch in a parallel circuit?
It is the same
32What is the relationship between current and voltage for a constant resistance?
Linear
33What is the formula relating voltage, current, and resistance?
$voltage = current \times resistance$
34Why does resistance increase as current increases in a resistor?
Collisions with atoms transfer energy, causing more vibrations that hinder electron flow
35How does temperature affect the resistance of normal wires?
Higher temperature increases resistance due to increased atomic vibrations
36Which component has a lower resistance at higher temperatures?
- Thermistor
- Resistor
- LDR
- Diode
37What are thermistors useful for?
Temperature detectors and thermostats
38How does the length of a wire affect its resistance?
Greater length results in more resistance
39How does cross-sectional area affect wire resistance?
Thinner wires give greater resistance because there is less room for electrons
40Which component has a resistance that is greatest when dark?
- LDR
- Thermistor
- Fixed Resistor
- Filament Bulb
41What are LDRs commonly used in?
Automatic night lights
42How do diodes affect current?
They allow current to flow freely in one direction and have high resistance in the opposite direction
43What can diodes be used for?
To get direct current output from alternating current input
44What is the total resistance of resistors connected in series?
The sum of the resistance in each component
45How does the total resistance of resistors in parallel compare to the smallest branch?
It is less than the branch with the smallest resistance
46What is the formula for electrical power involving current and voltage?
Power = Current x Voltage
47What is the formula for power using current and resistance?
P = I^2R
48What is the unit of electrical power?
Watts
49What is the formula for electrical energy involving charge and potential difference?
Energy = Charge x Potential~Difference
50What is the formula for electrical energy involving power and time?
Energy = Power x Time