AS LEVEL
PHYSICS
,17 Electric fields .......................................................3
17.1 Concept of an electric field .........................................3
Concept of an electric field ...........................................3
Electric field strength ....................................................4
17.2 Uniform electric fields .................................................5
Force on a charge .......................................................6
19 Current of electricity ...........................................8
19.1 Electric current ...........................................................8
Equation for current ...................................................11
19.2 Potential difference and power .................................13
Meaning of voltage ...................................................13
Electrical power .........................................................14
19.3 Resistance and resistivity ..........................................16
Electrical resistance ....................................................17
I-V characteristic for a metallic conductor ....................18
Resistance and temperature ........................................19
Resistivity ..................................................................22
20 D.C. circuits.......................................................25
20.1 Practical circuits .......................................................25
Internal resistance .....................................................26
20.2 Kirchhoff’s laws ......................................................28
Kirchhoff’s first law ....................................................28
Kirchhoff’s second law ...............................................29
Resistor combinations .................................................30
Solving problems with parallel circuits .........................32
, 17 E L E C T R I C F I E L D
In this topic, the concept of an electric field is introduced. This is further dev
the field and potential energy of point charges.
Awareness of the two types of charge and the processes of charging by fric
induction are useful prior knowledge.
1 7. 1 C O N C E P T O F A
ELECTRIC FIELD
LEARNING OUTCOMES
C ANDIDATES SHOULD BE ABLE TO:
A. understand the concept of an electric field as an example of a field of fo
electric field strength as force per unit positive charge acting on a statio
charge
Concept of an electric field
- Charged object experiences force in an electric field; this is what an electri
say there is an electric field anywhere where an electric charge experiences
electric field is a field of force.
- This is a rather abstract idea; you will be more familiar with idea of a ‘field
your experience of magnets. There is magnetic field around permanent ma
magnet placed nearby will experience a force. You have probably plotted fi
represent field around magnet; there is this type of force field which we ar
with, because we live in it - gravitational field. Our weight is force exerted
gravitational field of Earth; so we have:
PHYSICS
,17 Electric fields .......................................................3
17.1 Concept of an electric field .........................................3
Concept of an electric field ...........................................3
Electric field strength ....................................................4
17.2 Uniform electric fields .................................................5
Force on a charge .......................................................6
19 Current of electricity ...........................................8
19.1 Electric current ...........................................................8
Equation for current ...................................................11
19.2 Potential difference and power .................................13
Meaning of voltage ...................................................13
Electrical power .........................................................14
19.3 Resistance and resistivity ..........................................16
Electrical resistance ....................................................17
I-V characteristic for a metallic conductor ....................18
Resistance and temperature ........................................19
Resistivity ..................................................................22
20 D.C. circuits.......................................................25
20.1 Practical circuits .......................................................25
Internal resistance .....................................................26
20.2 Kirchhoff’s laws ......................................................28
Kirchhoff’s first law ....................................................28
Kirchhoff’s second law ...............................................29
Resistor combinations .................................................30
Solving problems with parallel circuits .........................32
, 17 E L E C T R I C F I E L D
In this topic, the concept of an electric field is introduced. This is further dev
the field and potential energy of point charges.
Awareness of the two types of charge and the processes of charging by fric
induction are useful prior knowledge.
1 7. 1 C O N C E P T O F A
ELECTRIC FIELD
LEARNING OUTCOMES
C ANDIDATES SHOULD BE ABLE TO:
A. understand the concept of an electric field as an example of a field of fo
electric field strength as force per unit positive charge acting on a statio
charge
Concept of an electric field
- Charged object experiences force in an electric field; this is what an electri
say there is an electric field anywhere where an electric charge experiences
electric field is a field of force.
- This is a rather abstract idea; you will be more familiar with idea of a ‘field
your experience of magnets. There is magnetic field around permanent ma
magnet placed nearby will experience a force. You have probably plotted fi
represent field around magnet; there is this type of force field which we ar
with, because we live in it - gravitational field. Our weight is force exerted
gravitational field of Earth; so we have:
