7 Science Chapter 14 Electric Current And Its Effects

Chapter Notes and Summary
• Common electric components are represented by symbols. Using these symbols, electric circuit can be expressed diagrammatically.
• An electric circuit mainly consists of (i) a source of electric energy (dry cell), (ii) a device that uses current
(bulb); connecting wires (conductors) and a device to open or close circuit (switch).
Symbols for some electric components
• To increase current, two or more cells are connected. Such a combination is called a battery. For this purpose, positive terminal of cell is connected to negative terminal of another cell.
• Electric circuit can be open or closed. In a closed circuit, current flows whereas no current flows whereas no current passes through a open circuit.
• When an electric current flows through a wire, wire gets heated. It is called heating effect of current. It depends on nature of wire, length, thickness and strength of electric current. Nichrome wire gets red hot on passing current through it. These are called elements.

Leave a Reply

Your email address will not be published. Required fields are marked *