Solved: Red laser light is incident on a double slit with a slit separation of 0.35 mm. A... [IB Physics (New syllabus)]

Question

SLPaper 2

Red laser light is incident on a double slit with a slit separation of 0.35 mm. A double-slit interference pattern is observed on a screen 2.4 m from the slits. The distance between successive maxima on the screen is 4.7 mm. Calculate the wavelength of the light. Give your answer to an appropriate number of significant figures.

[2]

Verified

Solution

$\lambda=\frac{4.7 \times 10^{-3} \times 0.35 \times 10^{-3}}{2.4}$ 1 mark

$=6.9 \times 10^{-7}$ «m» 1 mark

Explain the change to the appearance of the interference pattern when the red-light laser is replaced by one that emits green light.

[2]

Verified

Solution

green wavelength smaller than red 1 mark

fringe separation / distance between maxima decreases 1 mark

One of the slits is now covered. Describe the appearance of the pattern on the screen.

[3]

Verified

Solution

bright central maximum 1 mark

subsidiary maxima «on either side» 1 mark

the width of the central fringe is twice / larger than the width of the subsidiary/secondary fringes/maxima

**OR **

intensity of pattern is decreased 1 mark

Outline what is meant by the principle of superposition of waves.

[2]

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Solution

when 2 waves meet the resultant displacement 1 mark

is the «vector» sum of their individual displacements 1 mark

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Question

SLPaper 2

[2]

Verified

Solution

$\lambda=\frac{4.7 \times 10^{-3} \times 0.35 \times 10^{-3}}{2.4}$ 1 mark

$=6.9 \times 10^{-7}$ «m» 1 mark

Explain the change to the appearance of the interference pattern when the red-light laser is replaced by one that emits green light.

[2]

Verified

Solution

green wavelength smaller than red 1 mark

fringe separation / distance between maxima decreases 1 mark

One of the slits is now covered. Describe the appearance of the pattern on the screen.

[3]

Verified

Solution

bright central maximum 1 mark

subsidiary maxima «on either side» 1 mark

the width of the central fringe is twice / larger than the width of the subsidiary/secondary fringes/maxima

**OR **

intensity of pattern is decreased 1 mark

Outline what is meant by the principle of superposition of waves.

[2]

Verified

Solution

when 2 waves meet the resultant displacement 1 mark

is the «vector» sum of their individual displacements 1 mark

Still stuck?

Get step-by-step solutions with Jojo AI

Free

Want more practice questions for Physics (New syllabus)?