Electricity Flashcards
(60 cards)
What charge are protons neutrons and electrons
Protons positive
Neutrons no charge
Electrons negative
What does the number of protons determine
The element it is
How do you charge by friction
You get a neutral cloth and a neutral balloon then rub the cloth and the balloon together and electrons transfer from the cloth to the balloon causing a negatively further balloon and a positively charged cloth
What is the law of electrostatics
Opposite charges attract each other
Like charges repell each other
Why does a persons hair stand up when they touch a van de Graf on plastic
The person is negatively charged because the van de Graf is putting negative charge in to our body’s and because the person is standing on a plastic stall which is an insulator the charges have no where to go so therefor the hair sticks up because like forces repell once you get off the charges go into the earth and you become neutral again
Out of electrons neutrons and protons which can move
Electrons negatively charged
What makes up the nucleus
Protons and neutrons
WHen you have induced charges what do forces always do
Attract
What is the first way of charging by induction
You get a negatively charged rod and a neutral metal can bring the rod near to the can and the electrons will go to one side of the can causing a charged can
What is the third way of charging by induction
You get a positively charged rod and a metal ball suspended from insulating string you bring the ball close to the rod with your hand and negative electrons come out of the ground into the ball because they are attracted by the rod and then you remove your hand from the ball and the ball is per a toy charged negatively
What is the second way of charging by induction
You get a neutral ball and a posotively charged object bring that close to the ball and the electrons will attract and go through you into the earth leaving you with a posotively charged ball
What is a current
The rate of flow of charge per second
What is current measured in
Amps A
How do you calculate the current
Current (A) = charge (c)
time (s)
What are the symbols for time current and charge
Time T
Current I
Charge Q
What is the current equation rearranged
T = Q
I
Q = I * T
In a series circuit what is the same all the way round
The current
What is a full scale deflection
The biggest reading on an ammeter
Do bulbs use current in series
No it is the same throughout the circuit in series
What happens to the current in a parallel circuit if you measure it before the branches and in the branches
The amount in the branches should always add up to what the current was before the circuit split
What happens to the battery when you add more bulbs
It rises
What happens to the current in parallel circuit when you have 2 branches one has one bulb and the other has two bulbs
The current in the branch that only has one is higher than the other branch with two bulbs so brighter but it still adds up to the current before the branches are there
Battery current does not split equally
Most current in the branch with least bulbs
The battery current splits in ratio of bulbs
What is the equation for voltage
Voltage = energy
Charge
What is the symbol equation for voltage
V = E
Q
