Another resistor is made out of aluminum (= 3.5.107) with the same length and resistance as the one made out of gold. Is its cross section greater or smaller than that of the one made out of gold? Explain.

Which statement is not true about an extrinsic semiconductor? They do not have equal numbers charge carriers. Their impurities do not affect their electrical behavior. They can be doped with another element by a process known as doping process. They are chemically not pure. Their electrical properties can be tuned.

Plz answer correctly ....

C) The figure4 shows the relation between resistance and temperature for the thermistor.   What is the value of resistance approximately at 70°C? What happens to the resistance value as the temperature increases?                                          3.  Is it PTC or NTC thermistor? Justify your answer.