Notes On Electric Components - CBSE Class 7 Science
Circuit Diagram A simplified conventional pictorial representation of an electrical circuit, using standard symbols for electric components, is called a circuit diagram. A circuit diagram is also known as an electrical diagram, wiring diagram, elementary diagram or electronic schematic. Electrical Circuit A closed path formed by the interconnection of electrical components through which electric current flows is called an electrical circuit. A simple electrical circuit consists of a battery, a light bulb and a switch connected using connecting wires. If current does not flow through a circuit, then it is said to be an open or an incomplete circuit. Its switch is in ‘off’ position. A circuit is said to be a closed or a complete circuit when current flows through it. Its switch is in ‘on’ position. A combination of two or more cells connected together is called a battery. Batteries are used in many devices, such as torch lights, mobile phones, calculators and even automobiles. Symbols for Electrical Components Different symbols are used to represent different components of electrical circuits, but the symbols used must be standardised. These symbols are easy to understand, remember and draw.  Component Symbol Function of the Component Wire      ________ It allows current to flow from one part of the circuit to another. Switch When the switch is ON position, current will flow. When the switch is in OFF position, current will not flow. Cell It supplies electric current. The positive terminal (+) of a cell is represented by a vertical long line, while the negative terminal (-) is shown as a parallel, shorter line. Bulb The bulb glows if the switch is ON, and doesn’t glow if it is in OFF position. Battery It supplies electric current. A battery is a combination of two or more cells connected together.

#### Summary

Circuit Diagram A simplified conventional pictorial representation of an electrical circuit, using standard symbols for electric components, is called a circuit diagram. A circuit diagram is also known as an electrical diagram, wiring diagram, elementary diagram or electronic schematic. Electrical Circuit A closed path formed by the interconnection of electrical components through which electric current flows is called an electrical circuit. A simple electrical circuit consists of a battery, a light bulb and a switch connected using connecting wires. If current does not flow through a circuit, then it is said to be an open or an incomplete circuit. Its switch is in ‘off’ position. A circuit is said to be a closed or a complete circuit when current flows through it. Its switch is in ‘on’ position. A combination of two or more cells connected together is called a battery. Batteries are used in many devices, such as torch lights, mobile phones, calculators and even automobiles. Symbols for Electrical Components Different symbols are used to represent different components of electrical circuits, but the symbols used must be standardised. These symbols are easy to understand, remember and draw.  Component Symbol Function of the Component Wire      ________ It allows current to flow from one part of the circuit to another. Switch When the switch is ON position, current will flow. When the switch is in OFF position, current will not flow. Cell It supplies electric current. The positive terminal (+) of a cell is represented by a vertical long line, while the negative terminal (-) is shown as a parallel, shorter line. Bulb The bulb glows if the switch is ON, and doesn’t glow if it is in OFF position. Battery It supplies electric current. A battery is a combination of two or more cells connected together.

#### Activities

 Activity 1 Phet.colorado has created a good Java applet to undestand the concept of electric circuit. using this we can construct different electric circuits.  Go to Activity Activity 2 Sustainability.sellafieldsites.com has created a virtual lab activity to understand the construction of an electric circuit. using this we can arrange the electrical applliances, electrical sources, electrci conductors using the electric switches to make or break i.e. to close or open the electric circuits.  Go to Activity Activity 3 Phschool.com has created a virtual lab activity to understand the construction of an electric circuit. using this we can arrange the electrical applliances, electrical sources, electrci conductors using the electric switches to make or break i.e. to close or open the electric circuits.  Go to Activity Activity 4 Legacy.mos.org has created a virtual lab activity to understand the construction of the  electric circuits that is series and parallel electric circuits. using this we can arrange the electrical applliances, electrical sources, electrci conductors using the electric switches to make or break i.e. to close or open the electric circuits. Go to Activity

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