Physics 2a Flashcards
How is an object given a static charge?
This is caused when certain insulating objects give/receive electrons. Wherever the electrons move is given a negative charge.
What is current?
The flow of electrons around a circuit. Measured in Amperes (A).
What is potential difference?
The driving force around a circuit. Measured in Volts (V)
What is resistance?
Anything that slows the current in a circuit. Measured in Ohms (Appropriate Greek symbol).
What is work done?
Energy transferred.
What is the relationship between kinetic energy and potential difference?
Kinetic energy lost is potential energy gained.
What is work done to an elastic object stored as?
Elastic potential energy.
What is an elastic objects limit of proportionality?
The maximum length that it can be stretched before it won’t go back to its original shape.
What are the roles of ammeters and voltmeters?
To measure current and potential difference.
Why does resistance increase with temperature?
Some of the electrical energy is converted into heat energy. This causes ions in the conductor to vibrate more and in so making it harder for charged electrons to get through, reducing the current.
What is the role of an LED?
Give 2 uses.
They emit light when current passes through them in a forward direction. They indicate presence of current in a circuit. Uses: traffic lights, remote controls and digital clocks.
What happens in an LDR?
When light increases, the resistance decreases.
What is a series circuit?
All components are in a line, end to end between the positive and negative power supply.
What is a parallel circuit?
Each component is separately connected to the positive and negative of the power supply. If you remove one, you will hardly make a difference because the circuit is still complete.
What is represented by a curve on a VT graph?
A change in acceleration.
