Paper 2 Knowledge Gaps: Content more Flashcards
Define specific heat capacity
The amount of energy required to raise the temperature of 1 kg of a substance by 1 degree celsius
Define specific latent energy
The amount of energy that it takes to make 1 kg of a substance to change its state without a change in temperature
What is the difference between specific latent heat and specific heat capacity?
- specific heat capacity = change in temperature in the same state
- specific latent heat = change in state, not in temperature
How is pressure of a gas caused?
Pressure is caused due to the force on the walls of a container caused by moving particles hitting a wall
Describe the relationship of the temperature and the pressure of a gas
- higher the temperature of the gas = the more energy the molecules have
- collisions happen more often
- and happen with greater impact
- which increases the pressure
Define absolute zero
Particles at this temperature have no kinetic energy at all, so they remain perfectly still and don’t vibrate at all
What is the temperature of absolute zero?
-273 degrees celsius, or 0 kelvin
How do we convert between celsius to kelvin?
add 273
What is work done?
The transfer of energy through a force
How is work done on a gas?
- through compression
- force used to push a piston by a certain distance
- which decreases the volume of gas
- causing the molecules to move faster = more kinetic energy = increase in temperature
How does a gas do work?
- when a gas expands
- it loses energy
- resulting in a decrease of temperature
Why does the total resistance decrease in a parallel circuit when two or more circuits are connected?
Each additional resistor creates an extra pathway for the current to travel, which allows for more charge to flow overall and a smaller overall resistance
What is the role of the neutral wire?
- Forms the opposite end of the circuit to the live wire to complete the circuit
- much less dangerous than the live wire due to its low voltage
Explain the danger of a connection between the live and the earth wires
There is a large potential difference between the live wire (230V) and the earth wire (0V) and if the two are connected together, a large current can be created. If a person happens to be this connection, it can lead to a potentially lethal shock
Why is Earth’s magnetic north actually its geographic south pole?
- a compass is basically a suspended bar magnet
- its north pole lines up with that of the Earth’s geographic north pole
- which by the law of magnetic attraction cannot be right
- therefore, the north of the compass must be lining up with the Earth’s magnetic south
