WB JEE 2019 | Wave Optics Question 11 | Physics

WB JEE 2019

MCQ (Single Correct Answer)

-0.25

In Young's experiment for the interference of light, the separation between the slits is d and the distance of the screen from the slits is D. If D is increased by 0.5% and d is decreased by 0.3% then for the light of a given wavelength , which one of the following is true? "The fringe width ..............

increases by 0.8%

decreases by 0.8%

increases by 0.2%

decreases by 0.2%

WB JEE 2019

MCQ (Single Correct Answer)

-0.25

When the frequency of the light used is changed from $$4 \times {10^{14}}{s^{ - 1}}$$ to $$5 \times {10^{14}}{s^{ - 1}}$$, the angular width of the principal (central) maximum in a single slit Fraunhoffer diffraction pattern changes by 0.6 radian. What is the width of the slit (assume that the experiment is performed in vacuum)?

$$1.5 \times {10^{ - 7}}$$ m

$$3 \times {10^{ - 7}}$$ m

$$5 \times {10^{ - 7}}$$ m

$$6 \times {10^{ - 7}}$$ m

WB JEE 2018

MCQ (Single Correct Answer)

-0.25

If Young's double slit experiment is done with white light, which of the following statements will be true?

All the bright fringes will be coloured.

All the bright fringes will be white.

The central fringe will be white.

No stable interference pattern will be visible.

WB JEE 2017

MCQ (Single Correct Answer)

-0.25

Two monochromatic coherent light beams A and B have intensities L and $${{L \over 4}}$$, respectively. If these beams are superposed, the maximum and minimum intensities will be

$${{{9L} \over 4},{L \over 4}}$$

$${{{5L} \over 4}}$$ , 0

$${{{5L} \over 2}}$$ , 0

2L, $${{L \over 2}}$$

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