6.9 Conservation of Energy and Charge in Circuits

Question 1

Can charge be used up as it flows through a circuit?

Answer 1

Charge cannot be used up or lost

Question 2

Can current be used up or lost when flowing through a circuit?

Answer 2

Current is the rate of flow of charge so also can’t get used up or lost

Question 3

What is Kirchoff’s first law?

Answer 3

The total current entering a junction = the total current leaving it

Question 4

What is Kirchhoff’s second law?

Answer 4

The total emf around a SERIES circuit = the sum of the potential differences across each component

Question 5

What is the rule for calculating total resistance in a series circuit?

Answer 5

Rt = R1 + R2 + R3 ect

Question 6

What is the rule for calculating total resistance in a parallel circuit?

Answer 6

1/Rt = 1/R1 + 1/R2 + 1/R3 ect

Question 7

How do you calculate the total emf of cells in a series circuit?

Answer 7

εtotal = ε1 + ε2 + ε3 ect

Question 8

How do you calculate the total emf of cells in parallel?

Answer 8

Split the parallel circuit into series circuits and use the series circuit rule as εtotal is the same