P2

• Circuit Symbols

  A) open switch

  B) closed switch

  C) cell

  D) battery

  E) lamp

  F) ammeter

  G) voltmeter

  H) resistor

  I) variable resistor

  J) thermistor

  K) LDR

  L) diode

  M) LED

  N) fuse

  
• circuit

  A) current flows from positive side of cell

  
• OHM'S law 


  current is directly proportional to the potential difference
• • V is the potential difference in Volts (V).
  • I is the current in Amperes (A).
  • R is the resistance in Ohms (Ω).
• INVESTIGATING RESISTANCE AND LENGTH OF WIRE

  A) battery

  B) ammeter

  C) voltmeter

  D) crocodile clips

  E) wire being tested

  F) ruler

  
• I-V Graphs

  
• CURRENT

  A) 3A

  B) 1A

  
• POTENTIAL DIFFERENCE

  A) 4V

  B) 12V

  
• • LIVE WIRE – BROWN: Carries the ALTERNATING POTENTIAL DIFFERENCE from the supply and connected to the FUSE.
  • electric potential of 230V.
  • NEUTRAL WIRE – BLUE: Completes the circuit
  • electric potential of 0V
  • EARTH WIRE – GREEN AND YELLOW: used for SAFETY, to stop the appliance from becoming live
  • electric potential of 0V
• Transformers


  STEP-UP TRANSFORMERS = These INCREASE the POTENTIAL DIFFERENCE and DECREASE the CURRENT.

  STEP-DOWN TRANSFORMERS = These decrease the POTENTIAL DIFFERENCE and INCREASE the CURRENT.
• The National Grid

  A) power station

  B) step-up transformers

  C) national grid

  D) step-down transformers

  E) consumers