Notes from pg553-563

1. The amount of energy transferred depends on:

1. The potential difference of the power supply (amount of push)

2. The nature of the pathway through the loads that are using the electric potential energy.

2. Resistance - A measure of the opposition to the current flow in a circuit.

3. Ohm’s law:

         R = resistance (Ω), a measure of the opposition to the current flow in a circuit

         I = current (A), flow of charge

         V = voltage (V), electrical potential difference

4. Current has direct relationship with voltage in the resistor as long as other variables such as temperature are controlled.

5. Factors that determine resistance:

         1. Length, material ↑, resistance ↑

         2. cross- section area, cross-section area ↑, resistance ↓

         3. Material it is made of

         4. Temperature, temperature ↑, resistance↑

6. Series circuit – the loads are connected one after another in a single path, if one point of the circuit breaks, the whole circuit breaks too.

7. Parallel circuit – the loads are connected side by side, if one point breaks, the current can still go through other points, the whole circuit will not break.

8. Kirchhoff’s law: the total amount of current into a junction point of a circuit equals the total current that flows out of that same junction.

         IT = I1+I2+I3+I4+I5

9. Kirchhoff’s voltage law: the total of all electrical potential decreases in any complete circuit loop is equal to any potential increases in that circuit loop.

         VT = V1+V2+V3+V4+V5

10. Laws of conservation of electric charge and the conservation of energy: in any circuit, there is no net gain or loss of electric charge or energy.