Prepare a list of objects in your home under three categories: (i) Objects which are electrical insulators only (ii) Objects which are electrical conductors only (iii) Objects which are made of both, whose some parts are insulators and some electrical conductors
Expected categorization of household objects:
(i) Objects which are electrical insulators only: Rubber slippers, wooden furniture, plastic containers, glass bowls, ceramic cups, rubber gloves, plastic toys, wax candles, paper products, cloth items, plastic buckets, rubber bands, stone items, wooden doors, plastic combs.
(ii) Objects which are electrical conductors only: Metal spoons, aluminium foil, metal keys, coins, iron nails, copper vessels, metal jewellery, steel utensils, metal tools, silver items.
(iii) Objects made of both insulators and conductors:
Electric iron (metal sole plate is conductor, plastic handle is insulator).
Electric kettle (metal body is conductor, plastic handle is insulator).
Mobile phone (metal components inside are conductors, outer plastic/glass body is insulator).
Electric wires (copper wire inside is conductor, plastic covering is insulator).
Table fan (metal body and blades are conductors, plastic parts are insulators).
Plug and socket (metal pins are conductors, plastic body is insulator).
Switch (metal contacts inside are conductors, plastic cover is insulator).
Torch (metal contacts are conductors, plastic body is insulator).
Explanation
The chapter explains on pages 13-14 that 'The materials through which electric current can flow easily are called good conductors, or conductors of electricity' and 'The materials through which current cannot pass through are called insulators, or poor conductors of electricity.' It also states that 'Conductors and insulators are both important. Electrical wires, switches, connectors of plugs, and sockets are made of conductors. Insulators like rubber, plastics, and ceramics are used to cover wires, plug tops, and switches to protect people from electric shocks.'
Solution Steps
Category (i): Identify objects which are electrical insulators only - rubber slippers, wooden furniture, plastic containers, glass bowls, ceramic cups, rubber gloves, plastic toys, wax candles, paper products, cloth items, plastic buckets, rubber bands, stone items, wooden doors, plastic combs
Category (ii): Identify objects which are electrical conductors only - metal spoons, aluminium foil, metal keys, coins, iron nails, copper vessels, metal jewellery, steel utensils, metal tools, silver items
Category (iii): Identify objects made of both insulators and conductors - electric iron, electric kettle, mobile phone, electric wires, table fan, plug and socket, switch, torch