1In one house, four bulbs of 60 W each are lit for 3.5 hours every day. At Rs 8.50 for one unit, how much has to be paid as the bill for one month?
2Walk around the whole school building and identify the different electrical devices that have been used. Working in a group, prepare a report covering the job each device does and the condition it is in, and present it to the class.
3What is household electrification? Write the order in which electricity travels from the power house to a house.
4Why is the main switch also called the master switch, and how much current does it normally pass on?
5What is one unit of electricity? Write the formula used to find the energy consumed.
6Why is a fuse called a safety device? What is it made of, and write two of its properties.
7Write the difference between an MCB and a fuse.
8In a house the bulbs are joined in parallel, but disco lights are joined in series. What is the advantage of the parallel connection?
9Why are plugs and sockets used? Write their kinds.
10Why must care be taken when throwing away a broken bulb?