P4,P5 Flashcards
Draw an LDR?
Is it
Draw a diode?
Draw a resistor?
Draw
Draw a bulb?
Bulb
Draw a fuse?
Fuse
Draw a battery?
Battery
Draw a cell?
Cell
Draw a LED?
Led
Draw an ammeter?
Ammeter
Draw a thermister
Thermister
A voltmeter must be placed in a series or a parallel?
Parallel
Describe how a basic transformer is made?
The primary and secondary coil wrapped around an iron core
What is an electric current created chemically?
DC
Example of a use of thermistor?
To turn off the heater when house reaches a certain temperature
Examples of how to create static electricity?
Rubbing ruler/balloon on head
Examples of rectifiers?
Diodes
Explain how the resistance of a filament lamp changes as the potential difference across it?
As the PD across the filament lamp increases current also increases due to ohms law. Current flow also increases the lamp to heat up which causes resistance to as well
Formula for charge,current and time?
Q = It
Charge (c) = current(a) x time(s)
Formula for energy,charge and potential difference?
E = Qv
Energy = Q (coulombs) x V (volts)
Formula for Energy,power and time?
E = Pt
Energy (J) = Power(W) x Time(s)
Formula for power,current and resistance?
P = I^2R
Power = current^2 x resistance
How are electromagnets used in doorbells?
When the bell is pressed the switch is closed. This causes a current flow in the circut. A magnetjc feild is now produced. The iron contact is attracted to the electromagnet. When the contacts moves towards the magnetic feild the clapper hits the bell. Now no current
How can the voltage output from an alternator be doubled?
Double the speed
How can you get an electrostatic shock?
You get it when you are electrically charged and touch something earthed. You get charged by for example walking on carpet