ELECTRICITY Flashcards
(21 cards)
What are the two types of charge
Positive and negative
What is the relationship between charges
Unlike charges attract and like charges repel
What does charging a body involve
The addition or removal of electrons
What is the difference between a conductor and insulator
Conductors are materials which allow electrical current to flow through them easily. Metals are generally good electrical conductors. Insulators are materials which are poor conductors and do not allow electrical current to flow through them easily.
How do you calculate charge flow
Q= IT
What does each element stand for in the equation Q= IT
Q is charge flow in coulombs, I is current im amps and T is time in seconds
In a single closed loop, what is the current through the circuit
In a single closed loop the current is the same everywjere in a circuit
What is 1mA equal to
One-thousandth of an Amp, 1mA= 1/1000 A
In a television tube the picture is formed by streams of electrons hitting the screen. The current is 20 mA. How much electric charge hits the screen in 30 mins
Q=IT so Q=0.02x1800 Q=36C
In a lightning flash a typical amount of charge which reaches the earth is 10C. If the flash lasts 0.50 ms what is the current?
Q=IT so rearranging to I= Q/T meaning I= 10/ 0.0005 so I= 20,000 A
True or false, current gets used up by a bulb
False
Current is defined as the rate of flow of
Charge
1Amp of current means
One coulomb of charge flowing per second
The current in an electrical circuit is due to…
Negative electrons flowing from minus to plus
As bulbs are added in series circuit, the bulbs
Become dimmer
True or false the current in all parts of a parallel circuit is the same
False
True of false, adding more bulbs in parallel makes the battery current rise
True
True or false, adding more bulbs in series makes the current in the battery rise
False
A certain machine is very efficient, what does this mean
It wastes very little energy
What is the type of relationship between current and potential difference for a resistor at constant temperature
Ohmic
Which of these is a scalar quantity
/ displacement
/distance
/force
/velocity
Distance
