Everything Science Grade 11

CHAPTER 19. ELECTRIC CIRCUITS 19.3

1

Rp

=

�

1

R 1

+

1

R 2

+

1

R 3

�

=

�

1

10Ω

+

1

2Ω

+

1

1Ω

�

=

�

1 + 5 + 10

10

�

=

�

16

10

�

∴ Rp = 0,625Ω

See video: VPmje at http://www.everythingscience.co.za

See video: VPmkf at http://www.everythingscience.co.za

Use of Ohm’s Law in series and parallel Cir-

cuits

ESBIL

Example 4: Ohm’s Law

QUESTION

Calculate the current (I) in this circuit if the resistors are both ohmic innature.

V =12 V

R 1 =2 Ω

R 2 =4 Ω

I

SOLUTION

Step 1 : Determine what is required

We are required to calculate the current flowingin the circuit.

Step 2 : Determine how to approach the problem

Since the resistors are Ohmic in nature, we canuse Ohm’s Law. There are

however two resistors inthe circuit and we needto find the total resistance.

Step 3 : Find total resistance incircuit

Since the resistors are connected in series, the total resistance R is:

R = R 1 + R 2