Unit 6 - Waves

Flashcards for review

Who developed the unified theory of electromagnetism?

James Clerk Maxwell

What does Maxwell's theory combine?

Electricity and magnetism

What did Maxwell discover about light?

That it is an electromagnetic wave

Can electromagnetic waves exist without charges?

Yes, they can propagate through space

How are electric and magnetic fields oriented in EM waves?

They are perpendicular to each other and to the direction of motion

What is the speed of light in a vacuum?

Approximately 3 × 10^8 m/s

What is a wave?

A repeating vibration that transmits energy without moving matter

Name three examples of waves.

Water waves, sound waves, electromagnetic waves

What are mechanical waves?

Waves that need a medium to travel through

What are electromagnetic waves?

Waves of electric and magnetic fields that don't need a medium

What are matter waves?

Quantum waves associated with particles like electrons

What is the difference between transverse and longitudinal waves?

Transverse: vibration is perpendicular; Longitudinal: vibration is parallel

What is amplitude?

Maximum displacement from equilibrium

What is wavelength (lambda)?

Distance between successive crests or troughs

What is period (T)?

Time for one complete oscillation

What is frequency (f)?

Number of waves per second

What is the wave speed formula?

v = f × lambda

What is wave interference?

The combination of two or more waves at the same point

What is constructive interference?

When waves add to make a larger wave

What is destructive interference?

When waves cancel each other out

What is a standing wave?

A wave pattern formed by interference of two traveling waves in opposite directions

What are nodes in a standing wave?

Points that stay still

What are antinodes?

Points with maximum vibration

What is resonance?

When a system oscillates at its natural frequency with large amplitude

What determines the type of electromagnetic wave?

Frequency or wavelength

Do all electromagnetic waves travel at the same speed in a vacuum?

Yes, they all travel at speed c

What is polarization?

The orientation of the electric field of a light wave

What happens when unpolarized light passes through a polarizing filter?

Only light aligned with the filter’s axis passes through

What is Malus’ Law used for?

Calculating the intensity of light after passing through a polarizing filter

What did Young’s double-slit experiment prove?

Light behaves like a wave

What did the photoelectric effect prove?

Light also behaves like a particle

What are photons?

Quantum particles of light

What formula gives the energy of a photon?

E = hf or E = hc/lambda

Who explained the photoelectric effect?

Albert Einstein

What constant is used in photon energy calculations?

Planck's constant (h)