Electric current and it's effect

• What is a electric fuse?

  Wires made from some special materials melt quickly and break when large electric currents are passed through them. These wires are called electric fuses
• Why should fluorescent tubes and CFL need to be disposed off safely?

  Fluorescent tubes and CFLs contain mercury vapour, toxic in nature. Therefore, damaged fluorescent tubes or CFLs need to be disposed off safely
• Why should we gadgets have isi marking on them?

  It is advised to use electrical appliances and gadgets, which are electricity efficient. Bureau of Indian Standards, New Delhi assigns a Standard Mark on products, called ISI mark which is an assurance of conformity to the specifications given on the products. It is therefore suggested to use ISI mark products
• Name the product that have elements in them?

  immersion heaters, hotplates, irons, geysers, electric kettles, hair dryers, have elements inside them
• Why do wires need diffrent material lenght and thickness?

  The amount of heat produced in a wire depends on its material, length and thickness. Thus for diffrent requirements ,the wires of diffrent length, thickness and material are used
• What is a magnetic effect of a electric current?

  When an electric current flows through a wire, it behaves like a magnet. This is called the magnetic effect of a electric current
• What is a electromagnet?

  A current carrying coil of an insulated wire wrapped around a piece of iron is called an electromagnet.
• What is a heating effect?

  When an electric current flows through a wire, the wire gets heated. It is the heating effect of current.
• Fill in the blanks: (a) Longer line in the symbol for a cell represents its terminal______. (b) The combination of two or more cells is called a ________. (c) When current is switched ‘on’ in a room heater, it ______. (d) The safety device based on the heating effect of electric current is called a _____.

  (a) positive terminal

  (b)battery

  (c)gives out heat

  (d)electric fuse
• (a) To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell. (T/F) (b) When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. (T/F) (c) An electromagnet does not attract a piece of iron. (T/F) (d) An electric bell has an electromagnet. (T/F)

  (a)F

  (b)T

  (c)F

  (d)T