This is  popular among the candidates part(b) posed no problem to most responding  however, in pan (a) most of candidates lost the mark for not including very to quality km pressure and high  voltage
The expected  answers are:
                      
                        - Electrical  discharge through a gas at very low pressure and maintained m high voltage
 
                        - Two factors which determine the colour of  light in a fluorescent tube 
 
                        - Nature of  gas in the tube
 
                        - Nature of  powder coating inside the tube
 
                        - Voltage  across the tube.