CHAPTER 2

PHYSICS FOR JUNIOR HIGH SCHOOL IX

OPEN AND CLOSED ELECTRICAL CIRCUIT

PHYSICS FOR JUNIOR HIGH SCHOOL IX

CLOSED ELECTRICAL CIRCUIT

Closed electrical circuit is electric current in a circuit that can only flow in closed circuit.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

CLOSED ELECTRICAL CIRCUIT

a. The connectivity between current, potential difference, and resistance.

To see how they influence each other, George Simone Ohm (1789–1854) researched the connectivity between electrical potential (V), current (I), and Resistance (R). Mathematically, it can be stated as follows :

b. Specific resistanceResistance value of one medium depends on the following factors :

Wire length, the longer the wire, the bigger the resistance. Wire surface-are, the bigger the surface-area, the smaller

the resistance. Types of substance.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

CLOSED ELECTRICAL CIRCUIT

Here are some types of resistor in electricalcircuit : rheostat Colored-belt resistor Potentiometer

Specicfic resistence is a special property of one substance: conductor, isolator, semiconductor Conductor is anything that can flow electrical

current well. Isolator is anything that can’t flow electrical

current. Semiconductor is anything whose property

between conductor and isolator.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

CLOSED ELECTRICAL CIRCUIT

d. Ohm laws in closed electrical circuit

Current in that circuit can be counted by Ohm laws

PHYSICS FOR JUNIOR HIGH SCHOOL IX

OPEN ELECTRICAL CIRCUIT

B. OPEN CIRCUITOpen circuit is the contrary of closed circuit, in this circuit, there’s no any voltage difference. So that no electron movement that causes no electrical current. In this circuit, electron can not move to positive pole of voltage source, because it should not connect each other (disturbed). Lamp turned

offSwitch opened

PHYSICS FOR JUNIOR HIGH SCHOOL IX

THANK YOU