Waves 5 - Diffraction Grating

When the crest of one wave passes through the trough of another wave, ______ takes place.

• constructive interference

• destructive interference

• diffraction

• resonance

Interference of light is evidence that:

• the speed of light is very large

• light is a transverse wave

• light is electromagnetic in character

• light is a wave phenomenon

For destructive interference, the path difference is:

• odd number of half wavelengths

• even number of half wavelengths

• whole number of wavelengths

• even whole number of wavelengths

Constructive interference happens when two waves are:

• out of phase.

• zero amplitude.

• in phase.

Two waves with phase difference 180° have resultant of amplitude

• one.

• zero.

• same as the single wave.

• doubles the single wave.

Extra distance travelled by one of waves compared with other is called

• path.

• displacement.

• phase difference.

• path difference.

This image is representing what wave interaction?

• Refraction
• Diffraction
• Reflection
• Interference

Monochromatic light of wavelength 590 nm is incident normally on a plane diffraction grating having 4 × 10⁵ lines m⁻¹ . An interference pattern is produced.

What is the highest order visible in this interference pattern?

• 2

• 3

• 4

• 5

Light of wavelength λ is incident normally on a diffraction grating of slit separation 4λ.

What is the angle between the second order maximum and third order maximum?

• 14.5°

• 18.6°

• 48.6°

• 71.6°

The grating has a slit separation of 2.00 μm.

What is the angular separation (θ₂ – θ₁) between the first and second order maxima of the yellow light?

• 17.5°

• 36.9°

• 19.4°

• 54.3°