5.1 ELECTRIC FIELDS

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Understandings:

• Charge
• Electric Fields
• Coulomb's Law
• Electric Current
• Direct Current (dc)
• Potential Difference

Applications and skills:

• Identifying two forms of charge and the direction of the forces between them
• Solving problems involving electric fields and Coulomb's law
• Calculating work done in an electric field in both joules and electronvolts
• Identifying sign and nature of charge carriers in a metal
• Solving problems using the drift speed equation
• Solving problems involving current, potential differences and charge

Guidance:

• Students will be expected to apply Coulomb's law for a range of permittivity values

Utilization:

• Transferring energy from one place to another (see Chemistry option C and Physics topic 11)
• Impact on the environment from electricity generation (see Chemistry sub-topic C2 and Physics topic 8)
• The comparison between the treatment of electric fields and gravitational fields (see Physics topic 10) ​

Data booklet reference:​

Practice and review:
Drawing Electric Field Lines (Physics Classroom)

E Field lines

E Field Lines WS & SOLNs

5.1 Problem SET 1

5.1 Problem Set 1 solns

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5.2 HEATING EFFECT OF ELECTRIC CURRENTS

Understandings:

• Circuit diagrams
• Kirchoff's circuit laws
• Heating effect of current and its consequences
• Resistance expressed as R = V/I
• Ohm's law
• Resistivity
• Power dissipation

Applications and skills:

• Drawing and interpreting circuit diagrams
• ​Identifying ohmic and non-ohmic conductors through a consideration of the
• Solving problems involving potential difference, current, charge, Kirchhoff’s circuit laws, power, resistance and resistivity
• Investigating combinations of resistors in parallel and series circuits
• Describing ideal and non-ideal ammeters and voltmeters
• Describing practical uses of potential divider circuits, including the advantages of a potential divider over a series resistor in controlling a simple circuit
• ​Investigating one or more of the factors that affect resistance experimentally

Guidance:

• The filament lamp should be described as a non-ohmic device; a metal wire at • a constant temperature is an ohmic device
• The use of non-ideal voltmeters is confined to voltmeters with a constant but finite resistance 
• The use of non-ideal ammeters is confined to ammeters with a constant but non-zero resistance
• Application of Kirchhoff’s circuit laws will be limited to circuits with a maximum number of two source-carrying loop 

Utilization:

• Although there are nearly limitless ways that we use electrical circuits, heating and lighting are two of the most widespread 
• Sensitive devices can employ detectors capable of measuring small variations in potential difference and/or current, requiring carefully planned circuits and high precision components 

​​Data booklet reference:​

5.3 ELECTRIC CELLS

Understandings:

• Cells
• Internal resistance
• Secondary cells
• Terminal potential difference
• Emf

Applications and skills:

• Investigating practical electric cells (both primary and secondary) 
• Describing the discharge characteristic of a simple cell (variation of terminal potential difference with time) 
• Identifying the direction of current flow required to recharge a cell 
• Investigating combinations of resistors in parallel and series circuits
• Determining internal resistance experimentally 
• Solving problems involving emf, internal resistance and other electrical quantities ​

Guidance:

• Students should recognize that the terminal potential difference of a typical practical electric cell loses its initial value quickly, has a stable and constant value for most of its lifetime, followed by a rapid decrease to zero as the cell discharges completely

Utilization:

• The chemistry of electric cells (see Chemistry sub-topics 9.2 and C.6) ​

Data booklet reference: 

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5.4 MAGNETIC EFFECTS OF ELECTRIC CURRENTS

Understandings:

• Magnetic fields
• Magnetic force

Applications and skills:

• Determining the direction of force on a charge moving in a magnetic field
• Determining the direction of force on a current-carrying conductor in a magnetic field
  
• Sketching and interpreting magnetic field patterns
• Determining the direction of the magnetic field based on current direction 
  
• Solving problems involving magnetic forces, fields, current and charge
  

​​Guidance:

• Magnetic field patterns will be restricted to long straight conductors, solenoids, and bar magnets
  
  

Data booklet reference:

Practice and review:
​

5.1 Problem Set 1

Videos: