1. Tutorial Questions 1 to 8 Q = ItV = IR Series I 1 = I 2 = I 3 V T = V 1 + V 2 + V 3 R T = R 1 + R 2 + R 3 Parallel I = I + I 2 V 1 = V 2 = V 3 1 / R T = 1 / R 1 + 1 / R 2 Short cut if resistors are identical, divide by the number of resistors

2. Expt: For the 4 resistors 1. Measure resistance using an ohmmeter. 2. Find resistance using the colour code. Find tolerance. For the 33  resistor measure voltage and current then calculate resistance. ( The maximum current you can use is 0.25 A)

3. Revision P = IV P = V 2 ÷ R P = I 2 R E = Pt 1 2 0 V VtVt Potential divider V 1 = R 1 V T R T Tutorial questions 9 to 20

4. static electricity

5. How is Static Electricity Produced? An atom will usually have the same number of positives and negatives This makes the atom NEUTRAL. Proton (+) Neutron Electron (-) TG (HSD) Charging by rubbing

6. Electric Field – the space around a charge where electric forces can be detected. Field lines show the direction a positive charge would move in. The closer the lines the stronger the force.

7. Electrical potential difference, V, is the work done per unit charge. V = E w ÷ Q Therefore 1 V = 1 J/C One volt is when one joule of work is done in moving one coulomb of charge between two points. Electrical potential energy, Ew, is the work done in moving a charge from one point to another. - ++++++ ------ E w = Fd

8. - ++++++ ------ Remember total energy is conserved. Work done in moving charge from B to A = Electrical potential energy at A = Kinetic energy at B AB QV = ½mv 2 Tutorial Questions 1 to 8 on page 59 SAQ pages 1 to 8 Purple book Ex 4.7

9. buzzer Gains electrical E p Loss of electrical E p In battery chemical potential energy is changed to electrical energy. Bulb changes electrical energy to light and heat. Resistor changes electrical energy to heat. Heat is dissipated. Buzzer changes electrical energy to sound. Potential difference, pd (V) = loss in electrical energy per unit charge Electromotive force, emf ( E ) = gain in electrical energy per unit charge ( in J/C ) Read SAQ pages 13 and 16 Tutorial Qu 9 to 13