Electricity Flashcards
For the diagram of the atom name the parts.
See diagram
Which particles are in the nucleus of the atom?
Protons and neutrons
What happens if two positive charges are brought together?
They repel each other
What happens if two negative charges are brought together?
They repel each other
What happens if a positive and a negative charge are brought together?
They attract each other
What is electric charge?
An electric charge occurs when there are fewer or more electrons than protons.
Name one place that electrostatics can be used.
- Laser printers
- Paints spraying
- Cling film
- Forensic science
- Dust removal
- Electrostatic precipitators
- Electrostatic separators
Explain how electrostatics can be used in paint spraying a car.
- Car is connected to a negative terminal so that it is negatively charged.
- Spray gun is made positively charged so the paint particles are positive.
- The poistive paint is attracted to the negative car.
- Areas of the car already covered in paint will repel any more charged paint.
What is the effect of an electric field on a charge?
The charge will experience a force.
What does an electric field line show?
The direction a positive charge would move in that field.
What would the field lines around a positive point charge look like?
Field lines show direction away from the positive point charge.
What would the field lines around a negative point charge look like?
Field lines show direction towards the negative point charge
What would the field lines look between parallel plates?
Field lines run from positive to negative plate, with a bulge at the ends of the parallel plate.
How can you indicate a stronger electric field?
More field lines
How can you indicate a weaker electric field?
Fewer field lines
How is a uniform electric field represented?
Evenly spaced field lines
What would happen to an electron being fired through the electric field below?
It would experience a force and be attracted to the positive plate
What is current?
The charge transferred per second
What is d.c.?
Direct current. Charges move in one direction only.
What is a.c.?
Alternating current. The charges change direction constantly
Name one source of d.c.
A battery
Name one source of a.c.
Mains supply
What type of current is represented by this oscilloscope image?
d.c.
What type of current is represented by this oscilloscope image?
a.c.
How can you tell from this oscilloscope image that this is a.c.?
The trace shows a change in direction
What is meant by the potential difference (voltage) of a supply?
It is the number of Joules of energy given to each coulomb of charge passing through the cell
Which device measures current?
Ammeter
Which device measures voltage?
Voltmeter
Which devi measures resistance?
Ohmmeter
What is the symbol for an ammeter?
A circle with an A in it
What is the symbol for a voltmeter?
A circle with a V in it
What is the symbol for an Ohmmeter?
Circle with an Omega in it
How should an ammeter be connected to measure the current in a component?
In series
How should a voltmeter be connected to measure the voltage across a component?
In parellel
How can you identify a series circuit?
It is a circuit with only one path round it
What is the rule for current in a series circuit?
The current is the same everywhere
What is the rule for voltages in a series circuit?
The voltage across each component added together is equal to the supply voltage.
What happens if you unscrew one of the lamps in the circuit below? Why?
The other lamps go out. There is a break in the circuit and the current does not have a complete route to the battery.