Circuit Diagrams & Circuit Components | Physics for GCSE/IGCSE - Year 11 PDF Download

Circuit Components

Circuit symbols are vital in circuit diagrams, representing various components and their functions within a circuit.

• Each component in a circuit has a specific role and behavior that influences the flow of electricity.

Power supplies

• Power supplies such as cells, batteries, and generators deliver electrical current to a circuit.
• These sources of power are essential for the operation of electronic devices and systems.

Resistors

• Resistors like potential dividers, fixed resistors, and thermistors regulate the flow of current within a circuit.
• They control the amount of current passing through a circuit, affecting the overall performance.

Meters

• Ammeters and voltmeters are instruments used to measure current and voltage in a circuit.
• Ammeters are connected in series to measure current, while voltmeters are connected in parallel to measure voltage.
  • Ammeters are connected in series, while voltmeters are connected in parallel.

Electromagnetic Components

• Magnetising coils, relays, and transformers utilize electromagnetic effects.
• Relays use a small current in one circuit to control a larger current in another.
• Transformers can 'step up' or 'step down' current and potential difference.

Fuses

• Fuses safeguard costly components from current surges and serve as a safety precaution against fires.

Thermistors

• A thermistor is a type of resistor that is non-ohmic and its resistance varies based on temperature.
• Its resistance decreases as the temperature increases, and vice versa.
  • For instance, when the temperature rises, the resistance decreases, and conversely, when the temperature drops, the resistance increases.

Light-dependent Resistors

• A Light-dependent Resistor (LDR) is a type of resistor whose resistance alters based on the intensity of light it receives.
• As the illumination increases, the resistance of an LDR decreases.
• When exposed to higher light intensities, the resistance of the LDR diminishes correspondingly.

Diodes

• The circuit symbol for a diode can be recognized and drawn in addition to the previously mentioned information.
  
• Diodes may sometimes be depicted with a horizontal line across their center.
• When connected to an alternating current (a.c.) power supply, a diode allows current flow for half of the time, a process known as rectification.