Ch13 A-level Physics CIE

Superposition

What is the name of the principle that says you can add two waves together to make a new wave?

Diffraction

Which word means a wave spreading out when it hits an obstacle or goes through a gap?

Wavelength

Diffraction happens the most when the gap is the same size as the...

Interference

Which word means two waves superposing to create a new wave?

Constructive interference

Which term means the situation where two waves add together perfectly?

0

What is the phase difference of two waves which CONstructively interfere?

Destructive interference

Which term means the situation where two waves cancel each other out?

180 degrees

What is the phase difference of two waves which DEstructively interfere?

Path difference

If two waves are both arriving a point, which word means the distance one of the waves had to travel minus the distance the other wave had to travel?

It moves

What happens to the interference pattern when the two waves have slightly different frequencies?

Frequency

If two waves are coherent, they have EQUAL...

Phase difference

If two waves are coherent, they have CONSTANT...

Shine a laser through a double slit

How do you make two coherent sources of light?

Connect two speakers to the same signal generator

How do you make two coherent sources of sound?

Direct one microwave source at a metal plate with two gaps in it

How do you make two coherent sources of microwaves?

Fringes

Which word means the light and dark bands seen in the double-slit experiment?

Constructive interference

In the double-slit experiment, what kind of interference happens in the bright fringes?

Destructive interference

In the double-slit experiment, what kind of interference happens in the dark fringes?

Integer number of wavelengths (0, λ, 2λ, 3λ, etc...)

For the BRIGHT fringes in the double-slit experiment, the path difference equals...

Half integer number of wavelengths (λ/2, 3λ/2, 5λ/2, etc...)

For the DARK fringes in the double-slit experiment, the path difference equals...

λ = ax/D

What is the DOUBLE SLIT equation?

Wavelength

In the double slit equation, what does 'λ' mean?

Distance between the centres of the fringes

In the double slit equation, what does 'x' mean?

Distance between the centres of the slits

In the double slit equation, what does 'a' mean?

Distance from the midpoint of the slits to the screen

In the double slit equation, what does 'D' mean?

Diffraction grating

What do we call a slide with many equally spaced lines, very close to each other?

Maximum

What do we call a bright spot created by a diffraction grating?

0

What is the 'order number' of the central maximum created by a diffraction grating?

d sinθ = n λ

What is the DIFFRACTION GRATING equation?

Distance between the lines on the grating

In the diffraction grating equation, what does 'd' mean?

Angle of the maximum

In the diffraction grating equation, what does 'θ' mean?

Order of the maximum

In the diffraction grating equation, what does 'n' mean?

Wavelength

In the diffraction grating equation, what does 'λ' mean?

Dispersion

Which word means white light splitting into different colours?

Each colour has a different wavelength

Why does white light split into different colours when it passes through a diffraction grating?