Solve the following crossword puzzle with the help of clues given below:

Across 
 
1. Makes and breaks the circuit (6) 
3. A bulb with a broken filament (5) 
4. The material of the filament of a bulb (8) 
5. An insulator (7) 
7. Lights up on getting electrical energy from a cell (5) 

Down 

2. Materials that do not conduct electricity (9) 
6. A source of electricity (4) 
8. The closed path that allows the flow of current (4) 
9. An inert gas (5)