Electricity and Energy Flashcards
What is the formula to calculate charge?
Charge = current x time
Q=It
What direction does charge flow in a DC circuit?
One direction from negative to positive terminal
What direction does charge flow in an AC circuit?
Constantly changes direction
What is the equation for ohms law?
Voltage = current x resistance
V=IR
What is resistance (R) measured in?
Ohms
What is current (I) measured in?
Amperes (A)
What is an electric field?
An area which charged particles experience a force or attraction or repulsion
What happens when the lines of an electric field are closer together?
The field is stronger
Which way does a positive charge force go?
outwards
Which was does a negative charge force go?
Inwards
What are the rules for series circuit?
Current is the same everywhere
Voltage is split between components
What are the rules for parallel circuits?
Current is split between components
Voltage is the same everywhere
What is the rule for series resistance?
Rt= R1+R2…
What is the rule for parallel resistance?
1/Rt = 1/R1 + 1/R2…
What is a LED?
An electronic component that can produce light
Why must a LED always be connected to a resistor?
To protect the bulb from blowing up
What does MOSFET stand for?
Metal oxide semiconductor field effect transistor
What are the names for the three MOSFET terminals?
The gate, source and drain
What are the names for the three NPN transistor terminals?
The base, collector and emitter
When is the NPN transistor on?
When the input voltage is greater than or equal to 0.7V at the base
When is the MOSFET on?
When the input voltage is greater than or equal to 2V at the gate
What is power?
The rate at which energy is transferred
What is the equation for power?
Power = energy / time
P=E/t
What is power (P) measured in?
Watts (W)
What is energy measured in?
Joules (J)
What is a fuse?
A device which melts if the current in the circuit is too high it breaks the circuit and cuts the power supply
What is the equation to work out specific heat capacity?
Eh= cm/\T
What is the specific latent heat of a substance?
The amount of energy required it change the state of 1kg of a material
What is specific latent heat of fusion?
Solid to liquid
What is specific latent heat of vaporisation?
Liquid to gas
What is the equation to calculate specific latent heat?
Eh= ml
What is pressure?
The force per unit area
What is the formula for pressure?
Pressure= Force / Area
P=F/A
What is pressure (P) measured in?
Pascals (Pa)
What is force (F) measured in?
Newton’s (N)
What is the formula for Boyle’s Law?
P1V1 = P2V2
What is 0°C in kelvin?
273k
If temperature rises 1°C, what does it rise in kelvin?
1k
What is the formula for the pressure law?
P1/T1 = P2/T2
What is the formula for Charles’ law?
V1/T1 = V2/T2
What is work done?
The transfer of energy
What is the formula to calculate work done?
Word done = force x distance
Ew = Fd
What is the formula for gravitational potential energy?
Ep = mgh
What is the formula for kinetic energy?
Ek = 1/2mv2
