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Analysing Series and Parallel CircuitsBy Ms Nurul Ain Mat Aron

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identify series and parallel circuits

compare the current and potential difference of series circuits and

parallel circuits

determine the effective resistance of resistors connected in series

determine the effective resistance of resistors connected in parallel

solve problems involving current, potential difference and resistance in

series circuits, parallel circuits and their combinations

Objectives

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Series and Parallel Circuits

I

R

V

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Series Circuits

I1 I3

I2

The current, Ihas only one path to flow. Therefore, the current, I

passing through each resistor is the same.

I = I1= I2 = I3

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The potential difference across the two bulbs are shared between

them. Therefore,

V = V1+ V2

V1 V2

V

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I I

I I

IR1 R2

The current, Ipassing through each resistor is the same.

The potential difference, Vis directly proportional to the value of R

V = V1+ V2+ V3V = IR1+ IR2+ IR3

R = R1+ R2+ R3

Effective

resistance

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Series Circuits

I

6 R8

V

1.5 V A

Three resistors with resistance of 6 , 8 and R are arranged in series

with a battery of 6 V. The reading on the voltmeter connected across the 6

resistor is 1.5 V. Determine:

a) The reading on the ammeter

b) The value of R

c) The reading on the ammeter connected across the 8 resistor.

0.25 A

10

2 V

Problem 1

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Parallel Circuit

I1

I2

The current, Ihas more than one path to flow. Therefore, the current,

leaving and returning to the source is the sum of the currents in the

separate paths.

I = I1+ I2

The current splits

into 2 pathsThe current joins

back

I2

II

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The potential difference across the two bulbs is the same as they are

sharing the same two points, Pand Q. Therefore,

V=V1=V2

V

V1

V2P Q

R

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R2

R3

R1

V=V1=V2=V3

I = I1+I2+I3

Effective

resistance

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ElectricityExtra Problems

A current of 50mA flows in a conductor for 4 seconds. How mush electric

charge has passed through the conductor?

200 mC

Calculate the number of extra electrons gained by an object if it has a

negative charge of 4.8 x 10-12C. (charge of electron is -1.6 x 10-19C.)

Calculate the work down to move a charge of 5 C through a potential

difference of 8V.

4.0 x 10-5J

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Electricity

14V

56

I

Calculate:a) the resultant resistance in the circuit

b) The current in each resistor

c) The potential difference across each resistor

3

Extra Problems

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Electricity

4V

a) What is the total resistance of the circuit?b) Calculate the current , and

Extra Problems

2 4 6

I1 I2 I3

I1 I2 I3

12/11and 8/3 A

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Electricity

4V

4

I

Calculate:a) The total resultant resistance of the circuit

b) The current in the circuit

c) The potential difference across the resistors

6

Extra Problems

A

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Electricity

12V

10

I

Calculate:a) The potential difference across the 10resistor

b) The potential difference across R

c) The resistance of R

R

Extra Problems