Electricity: Circuits and their Components

About this chapter

Electricity: Circuits and their Components is Chapter 3 of Class 7 Curiosity. Through Nihal's class trip to the Bhakra Nangal Dam and the simple torchlight in his hand, students meet the basic building blocks of a circuit. The chapter builds these core ideas: a list of everyday uses of electricity under headings like cooking, lighting, transport, communication and heating-cooling; a strict caution against experimenting with mains supply and the rule to use only batteries or cells for school activities; the electric cell as a portable source with a positive (metal cap) and negative (metal disc) terminal; a battery as two or more cells joined positive-to-negative; the incandescent lamp with its filament that glows hot, and the LED with its longer positive wire and one-direction current; the cell holder and lamp holder; the idea of an electrical circuit as a complete path for current and the convention that current flows from the positive to the negative terminal of the cell; the switch as a simple device that completes (ON, circuit closed) or breaks (OFF, circuit open) the path; the standard symbols for cell, battery, lamp, LED, switch and wire, and the circuit diagram drawn with them; and finally conductors (metals, especially copper) and insulators (plastic, rubber, ceramic) and why the human body must be treated as a conductor of electricity. CTET Paper 2 Science tests this chapter through component-symbol pairings, will-the-lamp-glow circuit problems, LED orientation, conductor or insulator classification and two-switch reasoning. The four tests — Practice 15, Quiz 15, Hard 15, Mastery 30 — cover these ideas at exam depth.