Energy, power and resistance Flashcards
What is p.d
It is a measure of the transfer of energy by charge carriers
Characteristics of graph of ohmic conductor
Straight line and pass through the origin
Filament bulb behave the same way regardless of ____
Polarity
Some semi-conductor’s resistance drop as temperature increase, they are called to have a ___ __ _____
Negative temperature coefficient
Explain how does increasing temperature drop the resistance in some semi-conductor
The number density increase, as the number of charge carriers increase
What is a thermistor
A thermistor is an electrical component made from a semiconductor with negative temperature coefficient
5 uses of thermistor
*simple thermometers
*thermostats to control heating and air-conditioning units
*Monitor the temperature of components inside electrical device
*Measure temperature in electrical devices like kettle, toaster, freezer…
*Monitor engine temperature.
The drop in resistance of a thermistor as the temperature increase is __
Non-linear
A simple experiment to investigate the change in resistance of thermistor uses ____ and ____ ____
Ohmmeter and water bath
The circuit symbol for cell contain 1 long side and 1 short side. Which side is the positive end?
The long side
What does electromotive force described
EMF is used to describe the energy/work done on/to the charge carriers
What is the unit of electromotive force
Volts
Defined electromotive force
Electromotive force is defined as the energy transferred from chemical energy(or another form) to electrical energy per unit charge
Equation of electromotive force
E = W/Q
Q:charge
W:energy
What does electron gun produce?
A narrow beam of electron
