No. Semiconductor has negative temp coefficient, because increase in temp causes the increase in the k.e of the electrons bu t not in the no of electrons . these highly energised electronsel increase current, & in terms conductivity.
A: It is positive However for a diode it may reach zero but at a point not reasonable to be useful
positive, which is why they can easily self destruct
negative
Negative temperature coefficient of resistance means that as the temperature of a piece of wire or a strip of semiconducting material increases, the electrical resistance of that material decreases.
Temperature coefficient of the PN intersection voltage to balance the temperature coefficient of the warm voltage.
• ntc 'negative temperature coefficient': its resistance decreases as the temperature increases• ptc 'positive temperature coefficient': its resistance increases as the temperature increases
Yes, carbon has a negative temperature coefficient. -0.5*10^3/C
negative temperature coeeficient
What happens depends on the temperature coefficient of the diode. If that diode has a positive temperature coefficient, it resistance increases with increased temperature. A diode with a negative temperature coefficient does the opposite.
Negative temperature coefficient of resistance means that as the temperature of a piece of wire or a strip of semiconducting material increases, the electrical resistance of that material decreases.
negative 'temperature coefficient of reactivity'
The coefficient of viscosity of liquids decreases with an increases in temperature.
The diffusion coefficient depends on temperature in direct negative exponent.
ntc: negative temperature coefficient ptc: positive temperature coefficient
Temperature coefficient of the PN intersection voltage to balance the temperature coefficient of the warm voltage.
• ntc 'negative temperature coefficient': its resistance decreases as the temperature increases• ptc 'positive temperature coefficient': its resistance increases as the temperature increases
BJT & FET parameters are temperature dependent. In BJT the collector junction resistance decreasing ( collector current increasing) with temperature raise.Due to the highe temperature & current transistor will damage quickly. In FET drain resistance increasing (drain current decreasing ) with increasing temperature.Due to this property it will not damage easily. We can say from the above two statements FET is more temperature stable.FET can use in highe temperature applications.
positive temperature coefficient vs. negative temperature coefficient resistance increases or decreases with increase of temperature, respectively.
Thermal runaway is where the biasing and operating point is such that the temperature causes the gain to increase, which causes the temperature to increase, which causes the gain to increase, in a vicious circle, leading to destruction of the BJT. Proper biasing and gain management can prevent this from occurring.
Actually, the BJT is a positive temperature coefficient device. As they get warm, hFe increases, causing more current flow. This can lead to thermal runaway. That is why most class A common emitter configurations use an emitter resistor to place limits on the hFe demand, eliminating thermal drift and runaway.