Key Information Electricity Flashcards
What is the flow of electrical charge measured in?
Amperes (A)
This is referred to as Current (I).
What is the energy transferred per coulomb of charge measured in?
Volts (V)
This is referred to as Potential Difference (V).
What does resistance oppose and how is it measured?
Current, measured in ohms (Ω)
This is referred to as Resistance (R).
What is the basic equation known as Ohm’s Law?
V = I x R
In a series circuit, how does current behave?
Current is the same everywhere.
In a series circuit, how is potential difference treated?
Potential difference is shared.
How do you calculate total resistance in a series circuit?
R_total = R1 + R2 + …
In a parallel circuit, how is current distributed?
Current is shared between branches.
In a parallel circuit, how does potential difference behave?
Potential difference is the same across each branch.
What happens to resistance when more branches are added in a parallel circuit?
Resistance decreases.
Name three circuit components represented by symbols.
- Cell
- Battery
- Resistor
What does a resistor follow?
Ohm’s law (straight-line graph through origin).
How does the resistance of a filament bulb change with temperature?
Resistance increases as temperature increases.
What is a key characteristic of a diode?
Current flows in one direction only.
How does the resistance of a thermistor change with temperature?
Resistance decreases as temperature increases.
What is an LDR?
A Light Dependent Resistor whose resistance decreases as light intensity increases
LDRs are commonly used in light-sensing applications.
What is a characteristic of series circuits?
One path for current; if one component breaks, the circuit stops
Series circuits are often used in applications where the same current is required through all components.
What is a characteristic of parallel circuits?
Multiple paths; if one branch breaks, the rest still work
Parallel circuits are commonly used in household wiring to ensure that devices can operate independently.
What is the purpose of the National Grid?
Transfers electricity from power stations to homes
The National Grid ensures the efficient distribution of electricity across vast distances.
What do step-up transformers do?
Increase voltage to reduce energy loss
Step-up transformers are crucial for long-distance electricity transmission.
What do step-down transformers do?
Reduce voltage for safe use at homes
Step-down transformers ensure that the voltage is at a safe level for household appliances.
What is the UK mains supply voltage and frequency?
230 V, 50 Hz (alternating current - AC)
This standard is important for compatibility with electrical devices in the UK.
What is DC?
Direct current; flows in one direction (e.g., batteries)
DC is commonly used in low-voltage applications such as electronics and batteries.
What is AC?
Alternating current; changes direction (used in mains)
AC is preferred for power distribution because it can be easily transformed to different voltages.
