Everything Science Grade 10

17.5 CHAPTER 17. ELECTRIC CIRCUITS

we have that:

RS=R 1 +R 2 +...

RS=R 1 +R 2

= 750kΩ + 1, 7 MΩ

= 750× 103 Ω + 1, 7 × 106 Ω

= 0, 75 × 106 Ω + 1, 7 × 106 Ω

= 2, 45 × 106 Ω = 2, 45 MΩ

Step 3:Quote the final result

The total resistance of the resistors in series is 2 , 45 MΩ.

Parallel resistors ESAFK

When we add resistors in parallel to a circuit:

• There are more paths for current to flow which ensures that thecurrent splits
  across the different paths.


• The voltage isthe sameacross the resistors. The voltage across the battery in
  the circuit is equal to the voltage across each of the parallel resistors:

Vbattery=V 1 =V 2 =V 3...

• The resistance to the flow of currentdecreases. The total resistance,RPis given
  by:
  1
  RP =

1

R 1 +

1

R 2 +...

When resistors are connected in parallel the start and end points for all the resistors are the

same. These points have the same potential energy and so the potential difference between

them is the same no matter what is put in between them. You can have one, two or many

resistors between the two points, the potential difference will not change. You can ignore

whatever components are between two points in a circuit when calculating the difference

between the two points.

296 Physics: Electricity and Magnetism