10. Electrical circuits

Answer 1

• Kirchoffs first law is conservation of charge applied to an an electrical circuit

Answer 2

• Kirchhoff’s second law is conservation of energy applied to an electrical circuit
• The total energy transferred to the charges in a circuit is always equal to the total energy transferred from the charge in a closed loop
• It states in any circuit, the sum of electromotive forces is equal to the sum of the p.d.s around a closed loop
• A closed loop can be thought of as a single possible path for the current

Question 3

Example of the 2nd law

Answer 3

• Cell provides p.d. to each loop - V1 = V2 + V3

Answer 4

• A series circuit has only one path for the current, a single loop from one terminal of source of e.m.f. (e.g. cell) back to the other terminal
• In a series circuit, the current is the same in every position (rate of flow of charge is the same at all points in the circuit - kirchoff’s law)