A torch bulb has two terminals and a cell has also two terminals. In which case the two terminals are not marked $+$ and $-$? 

What are conductors? Give two examples of conductors.

Name a device which is used to 'open' or 'close' a circuit? (Switch/Bulb)

Name the portable electric lamp which works with cells.

Why are metal wires used to carry electricity? 

What is the scientific name of the materials which allow electricity to pass through them?

In an electrical appliance, which type of material is used to make that part of the appliance which is to be handled by us?