Std -12 _ Chap 19 - Diffraction of light waves

A slit of width a is used to observe a diffraction pattern on a screen at a distance L from the slit.If the width of the slit were doubled, the width of the central bright band would

• decrease by a factor of 4

• decrease by a factor of 2

• increase by a factor of 2

• increase by a factor of 4

Light of wave length 3.5x10² nm is incident on a slit of width 0.5mm . Which of the following expressions corresponds to the angle at which the second order minimum is formed

• sinθ= 2.2 x 10 ^-4

• sinθ= 3.5 x 10 ^-4

• sinθ= 1.1 x 10 ^-3

• sinθ= 1.4 x 10 ^-3

Light of wavelength 2. 5 x 10 ²nm is incident on a slit of width 0.3 mm. What order of dark band corresponds to

sinθ = 2. 5 x 10 ^-3

• 4

• 3

• 2

• 1

The table lists the range of wavelengths in vacuum corresponding to a given color.Which one of the colors will produce a diffraction pattern with the widest central maximum, assuming all other factors are equal?

• Red ( 780-622 nm)

• Yellow ( 597-577 nm)

• Green ( 577-492 nm)

• Blue ( 492-455 nm)

Diffraction occurs when light passes through a single slit. Rank the following three choices in decreasing order, according to the extend of the diffraction that occurs(largest diffraction first )

1. Blue light , narrow slit
2. Red light , narrow slit
3. Blue light , wide slit

• 1,2,3

• 2,1,3

• 3,1,2

• 1,3,2

In a single slit diffraction experiment the width of the slit is reduced . What happens to the width of the central bright fringe in the resulting diffraction pattern

• Stays the same

• It becomes narrower

• it becomes wider

• the central bright fringe disappears

A single slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the wavelength of the illuminating light is doubled?

• It will be cut to one -quarter its original size

• It will be cut in half

• It will double

• It will become four times as large

A single slit diffraction pattern is formed on a distant screen . Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the slit width is doubled ?

• It will be cut to one -quarter of its original size

• it will be cut in half

• it will double

• It will become four times as large

Light of wavelength 300nm shines through a single slit of width 2 μm and falls on a flat screen , located 3m from the slit.Which of the following is true about the diffraction pattern?

• The central bright band is wider and brighter than the other bands

• The central bright band is wider and dimmer than the other bands

• The central bright band is narrower and brighter than the other bands

• The central bright band is narrower and dimmer than the other bands

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-5

Light of wavelength 300nm shines through a single slit of width 2 μm and falls on a flat screen , located 3m from the slit.What is the width of the cental band?

• 3. 0 x 10^-1m

• 4. 5 x 10^-1m

• 6. 0 x 10^-1m

• 9. 0 x 10^-1m