Everything Science Grade 10

CHAPTER 17. ELECTRIC CIRCUITS 17.5

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Results and conclusions:

• Compare the currents through individual resistors with each other.


• Compare the sum of the currents through individual resistors with the current
  before the parallel branches.


• Compare the various voltage measurements across the parallel resistors.

Example 11: Parallel resistors I

QUESTION

A circuit contains two resistors in parallel. The resistors have resistance values of

15 Ωand7 Ω.

15 Ω 7 Ω

What is the total resistance in the circuit?

SOLUTION

Step 1:Analyse the question

We are told that the resistors in the circuit are in parallel circuit and that

we need to calculate the total resistance. The values of the two resistors

have been given in the correct units,Ω.

Step 2:Apply the relevant principles

The total resistance for resistors in parallel has been shown to be the

Physics: Electricity and Magnetism 305