Physics Flashcards
what is an electric current?
An electric current is a flow of electric charge
What is meant by potential difference and resistance in a circuit?
The potential difference between two points in an electric circuit is the work done when a coulomb of charge passes between the points total resistance of a number of resistors in series is equal to the sum of all the individual resistances.
Does the resistance of the LDR increase with the light’s intensity?
Yes, it does.
Name and give the colors for the 3 wires and 3 core table. Why are they color coded?
Live wire-Brown
Neutral wire-blue
Earth wire-green and yellow
The color shows its purpose and makes it easy to identify
Why is touching live wire dangerous?
It is dangerous because our bodies are at OV that means that if we touch it there will be a large potential difference and produce a current through you, creating an electric shock
Name one linear component and one non-linear component.
In an electric circuit, a nonlinear element or nonlinear device is an electrical element which does not have a linear relationship between current and voltage
What is the potential difference and frequency of the UK mains supply?
Mains electricity is an AC supply, with the UK mains supply being about 230 V. It has a frequency of 50 Hz (50 hertz), which means it changes direction, and back again, 50 times a second.
What is the national grid?
electricity is distributed from power stations to consumers through the National Grid
What is SPECIFIC LATENT HEAT?
how much energy is needed to heat or boil something.
What are transverse waves?
In transverse waves, the oscillations are at right angles to the direction of travel and energy transfer.
Light and other types of electromagnetic radiation are transverse waves. All types of electromagnetic waves travel at the same speed through a vacuum, such as through space.
Water waves and S waves are also transverse waves.
What are longitudinal waves?
Longitudinal waves
In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer.
Sound waves and waves in a stretched spring are longitudinal waves. P waves are also longitudinal waves.
What is the main difference between AC and DC powers?
AC- generated by power stations
DC- portable (direct current)
Is wood renewable?
It is if it can be replaced
What are the two things that come from fossil fuels?
Global warming- CO2
Acid rain-SO2
Why does the national grid need high voltage?
It needs high voltage to generate power and so that the current decreases. I current is higher than voltage than there will be a lot of energy lost through heat.
Why do we boil the water in a boiler?
We boil the water as it has more energy when it becomes steam.
why does the generator turn?
To turn a magnet in a coil to create power
Why do we decrease the current?
If we lower the current the less the collisions the less the heat loss.
What is the amount of V AC and HZ used in a home?
230V HZ AND 50HZ
What are the advantages and disadvantages of nuclear energy?
PROS: -green -no pollution
CONS: -nuclear waste -must be buried in concrete and led to not release any radiation
What will a white dwarf turn into and why haven’t we seen one?
It will turn into a black dwarf and we haven’t seen it because there hasn’t been enough time for it to happen as the earth is only 13.7 billion years old.
What causes galaxies to spin?
Black holes
Why is a white dwarf white?
Due to the heat and the energy
What is the frequency?
Number of waves per sec and it’s measured in hertz
Sound waves are what waves?
Longitudinal waves
