Module 4- Waves :)

What is a progressive wave?

A wave that transfers energy from one place to another

What is a transverse wave?

A wave where the particles oscillate perpendicular to the direction of propagation of the wave

What is a longitudinal wave?

A wave where the particles oscillate parallel to the direction of propagation of the wave

What is the displacement of a wave?

Distance of a point on the wave to the equilibrium position

What is the amplitude of a wave?

Maximum displacement from the equilibrium

What is the wavelength of a wave?

The maximum distance between 2 points in phase

What is the time period of a wave?

The time taken for one complete oscillation

What is the frequency of a wave?

The number of cycles per unit time

What is the wave speed of a wave?

The distance travelled by a wave per unit time

What is phase difference?

how far out of sync two points on a wave are

What is the equation for phase difference?

distance between 2 points/wavelength x 360

What does voltage represent in an oscilloscope?

Amplitude

When does reflection occur?

Angle of incidence=angle of reflection

When does refraction occur?

When a wave changes direction and speed as it moves from one medium to another

What remains constant in refraction?

Frequency

What is diffraction?

The spreading out of a wave as it passes through a gap or by an obstacle

What is intensity?

Power transmitted per unit area

What is intensity equal to when it is in a sphere?

I=P/4pi(r²)

What is intensity proportional to?

Amplitude²

What are some properties of EM waves?

They can travel though a vacuum, travel at the speed of light, and are transverse waves

When is a wave plane polarised?

When the particles only oscillate in one plane

Why can longitudinal waves not be polarised?

They are already polarised

What is the refractive index?

The ratio of the speed of light in a vacuum to the speed of light in a substance

What is the equation for refractive index?

n=speed of light in vacuum/speed of light in the substance

What happens to light when it goes into a material with a higher refractive index?

Bends towards the normal

What happens to light when it goes into a material with a lower refractive index?

Bends away from the normal

What graph should you plot in the determining refractive index practical? How should you determine the refractive index?

sinx₁ against sin x₂. Refractive index is gradient.

When does Total Internal Reflection occur?

When the ray travels to a material with a lower refractive index, and the angle to the normal is 90 degrees

What is the critical angle?

The angle where the ray travels at 90 degrees to the normal