# Intermediate 2 physics Electricity an electronics

## 17 terms

### Charge

(Q) the amount of electricity traveling through a circuit.
it is measured in coulombs (C)

### Current

(I) is the amount of charge passing in unit time (1s).
I = Q / t it is measured in amperes (A)

### Ammeter

is placed in line (in series) with the circuit.

### Voltage

is a measure of the energy givin to the charges in a circuit.

### Voltmeter

is placed across (in parallel with) the component being measured.

### Resistance

is when materials oppose charges passing through them. Increasing the resistance of a circuit decreases the current.
R = V / I

### Series circuits

have all the components in a row or loop.There are no branches there is onlt

### Potential divider circuit

use 2 or more resistors or a potentiometer to provide a part of a voltage.

### Parallel circuits

have more than one path for the charges to follow

### Power

is the rate at which energy is transformed
P = E / t

### Energy

how many joules of electrical energy have been transformed?
E = Pt

### Direct Current

Electrons move in only one direction.

### Alternating Current

Electrons movement is back and forth.

### Light emitting diodes (LED)

are made from two semi-conductor materials. When electrons cross the junction in the correct direction it emits --light. The diode symbol has to 'point' from + to - from a power supply.

### The thermistor

as the temperature increases, its resistance decreases.

### The light dependent resistor (LDR)

as the light increases its resistance decreases.

### Amplifier

the purpose of it is to increase the amplitude of an electrical signal.