Electricity and Electromagnetic Waves Review

Practice flashcards covering the basics of electricity, circuits, Ohm's Law, wave properties, and the electromagnetic spectrum based on physics lecture notes.

What is the definition of electric current?

The flow of electric charges.

What is the unit used to measure electric current?

Ampere ($A$).

What is the role of voltage in an electric circuit?

It pushes electric charges through a circuit.

What is the unit of measurement for voltage?

volt ($V$).

How is resistance defined?

It opposes the flow of current.

What is the unit of measurement for resistance?

ohm ($\Omega$).

What is the formula for Ohm's Law?

$V = I \times R$ (where $V$ is voltage, $I$ is current, and $R$ is resistance).

What is the formula for Electrical Power?

$P = V \times I$.

What is the unit of Electrical Power?

WATT ($W$).

What is the main difference between a series circuit and a parallel circuit regarding paths for current?

A series circuit has one path for current, while a parallel circuit has multiple paths for current.

In a series circuit, what happens if one bulb breaks?

All bulbs turn off.

Where are parallel circuits commonly used?

In houses.

How do electrons flow in a circuit relative to its terminals?

Negative to positive.

What are the components of a simple circuit?

Source, wires, switch, and load.

What is a wave?

A way energy moves from one place to another.

Define the crest and the trough of a wave.

The crest is the highest point of a wave, and the trough is the lowest point of a wave.

What is the relationship between a wave's amplitude and its energy?

Bigger amplitude means more energy; smaller amplitude means less energy.

How is wavelength defined?

The distance between two waves, measured from crest to crest or trough to trough.

What is frequency?

The number of times a pattern repeats in a specified amount of time.

What identifies the specific use of an electromagnetic device?

Either its frequency or its wavelength.

What is the electromagnetic spectrum?

The range of frequencies of electromagnetic radiation.

Which part of the EM spectrum has the longest wavelength and lowest frequency?

Radio waves.

What is the wavelength range for radio waves?

$7.1 \times 10^{-2}\,m$ to several kilometers.

What are some applications of microwaves?

Cell phone transmission, bluetooth, wifi box, cooking, and radar.

How do humans experience infrared radiation?

It is invisible to humans, but it is felt as heat.

What is the wavelength range for visible light?

$4 \times 10^{-7}\,m$ to $7.5 \times 10^{-7}\,m$.

What color sequence makes up visible light?

ROY-G-BIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet).

What are the harmful effects of ultraviolet (UV) radiation?

Sunburn and skin cancer.

What is the primary use of X-rays in technology?

X-ray machines that allow us to see through skin for medical diagnosis.

Which part of the EM spectrum has the shortest wavelength and highest frequency?

Gamma rays.

What is the characteristic of non-ionizing radiation?

It has low energy and cannot remove electrons from atoms (no ionization).

What are the dangers of ionizing radiation?

It can remove electrons from atoms and damage cells and DNA.