Give the construction and working of an electic torch?
take 4 lengths of electric wire with differently colored plastic coverings.remove a little of the plastic covering from each length of the wire at the ends. this would expose the metal ires at the ends of each length . fix the exposed parts of 2 wires to an electric cells and the other two of the bulb.you can stick the wires to the bulb with the tape used by electricians. use rubber bands or tape to fix the wires to the cells. now connect the wires to the bulb with those attached to the cells