Electricity Physics Flashcards
What are the protective measures for devices and users in domestic appliances?
Insulation, double insulation, earthing, fuses, and circuit breakers
These measures ensure safety by preventing electric shocks and equipment damage.
What happens when current flows through a resistor?
Electrical energy transfer and an increase in temperature
This effect is utilized in various domestic applications.
What is the formula for power in an electrical circuit?
Power = Current × Voltage
This formula is crucial for selecting appropriate fuses.
How is energy transferred in an electrical circuit?
Energy transferred = Current × Voltage × Time
This formula helps calculate the total energy consumed.
What type of current is used in mains electricity?
Alternating Current (AC)
AC is the standard form of electricity supplied to homes.
What type of current is supplied by cells or batteries?
Direct Current (DC)
DC is commonly used in portable devices.
What factors determine the suitability of different circuits for applications?
Applied voltage and the number/nature of components
This influences circuit design for specific functions, like domestic lighting.
How does changing resistance affect current in a circuit?
Changing resistance affects current flow
This relationship is governed by Ohm’s Law.
What does the resistance of Light Dependent Resistors (LDRs) vary with?
Light intensity
LDRs are used in light-sensitive applications.
What do thermistors change resistance with?
Temperature
This makes thermistors useful for temperature sensing.
What is the formula relating voltage, current, and resistance?
Voltage = Current × Resistance (V = IR)
This is known as Ohm’s Law.
What is current defined as?
The rate of flow of charge
This is measured in Amperes (A).
What is the formula for charge in relation to current?
Charge = Current × Time (Q = IT)
This relates charge flow over a period.
What is true about voltage across parallel components?
Voltage across parallel components is the same
This is a key characteristic of parallel circuits.
What principle states that current is conserved at junctions in a circuit?
Conservation of current at junctions
This is known as Kirchhoff’s junction rule.
What does voltage represent in an electrical context?
Energy transferred per unit charge
It is measured in Volts (V).
What is the equivalent of 1 Volt in Joules and Coulombs?
1 Volt = 1 Joule per Coulomb
This defines the relationship between voltage, energy, and charge.
What is the formula for energy transferred in terms of charge and voltage?
Energy transferred = Charge × Voltage (E = QV)
This formula is used to calculate energy consumption in circuits.
