Unit14-3

What is the order of colors in the visible spectrum (low to high frequency)?

Red, Orange, Yellow, Green, Blue, Violet (ROYGBV; ~400–700 nm).

How are wavelength and frequency related for EM waves?

λf = c. Higher f → shorter λ (e.g., violet light has higher f than red).

Classify EM radiation with λ = 1 cm.

Microwaves (range: ~1 mm to 1 m).

What causes constructive interference?

Path difference Δℓ = mλ (waves in phase).

What causes destructive interference?

Define diffraction.

Bending/spreading of waves when passing through an aperture or around obstacles.

How does single-slit diffraction differ from double-slit interference?

Single slit: Wide central max with dimmer side fringes. Double slit: Evenly spaced bright/dark fringes.

How does decreasing slit separation (d) affect the fringe pattern?

What is the path difference for the 3rd dark fringe?

Why does the central maximum in single-slit diffraction have the highest intensity?

All wavelets interfere constructively at θ = 0.

What happens to the central max width if slit width decreases?

It widens (diffraction increases).

Pitfall: "Light travels faster in denser media."

Correction: Light slows down in denser media (v = c / n).

Write the double-slit bright fringe formula.

What is the condition for destructive interference?

How is the EM spectrum ordered (long to short λλ)?