Ayellow led is to be used with a 9v battery. calculate the series resistor from e34 series required to limit the current to approximately 20ma if the forward voltage drop across the led is 2.5v

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?