# Electric Components : Science NCERT Notes

### 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.
For a bulb to glow, it must be connected to battery rather than a cell, because a bulb will require more power. So if a circuit requires more power, then a battery should be connected.

### Cell Holder

A compartment that holds two or more cells together to form a battery is called a cell holder.

### Open Circuit

If current does not flow through a circuit, then it is said to be an ‘open’ circuit or incomplete. Its switch is in ‘off’ position.

### Closed Circuit

A circuit is said to be a closed circuit or complete when current flows through it.
Its switch is in ‘on’ position.

### Battery

A combination of two or more cells connected together is called a battery. It is formed by connecting the positive terminal of one cell to the negative terminal of another. To identify the positive and negative terminals, they are denoted as + and –, respectively. These batteries are used in many devices, such as torch lights, mobile phones, calculators and even automobiles.

### Symbols

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.

#### 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.