JEE Main 2019 (Online) 10th January Morning Slot | Ray & Wave Optics Question 191 | Physics

JEE Main 2019 (Online) 10th January Morning Slot

MCQ (Single Correct Answer)

-1

In a Young’s double slit experiment with slit separation 0.1 mm, one observes a bright fringe at angle $${1 \over {40}}$$ by using light of wavelength $$\lambda $$₁. When the light of wavelength $$\lambda $$₂ is used a bright fringe is seen at the same angle in the same set up. Given that $$\lambda $$₁ and $$\lambda $$₂ are in visible range (380 nm to 740 nm), their values are -

400 nm, 500 nm

625 nm, 500 nm

380 nm, 500 nm

380 nm, 525 nm

JEE Main 2019 (Online) 10th January Morning Slot

MCQ (Single Correct Answer)

-1

A plano convex lens of refractive index $$\mu $$₁ and focal length ƒ₁ is kept in contact with another plano concave lens of refractive index $$\mu $$₂ and focal length ƒ₂. If the radius of curvature of their spherical faces is R each and ƒ₁ = 2ƒ₂, then $$\mu $$₁ and $$\mu $$₂ are related as -

$$3{\mu _2} - 2{\mu _1}$$ = 1

$${\mu _1} + {\mu _2}$$ = 3

$$2{\mu _1} - {\mu _2}$$ = 1

$$2{\mu _2} - {\mu _1}$$ = 1

JEE Main 2019 (Online) 9th January Evening Slot

MCQ (Single Correct Answer)

-1

In a Young's double slit experiment, the slits are placed 0.320 mm apart. Light of wavelength $$\lambda $$ = 500 nm is incident on the slits. The total number of bright fringes that are observed in the angular range $$-$$ 30^o$$ \le $$$$\theta $$$$ \le $$30^o is :

640

320

321

641

JEE Main 2019 (Online) 9th January Evening Slot

MCQ (Single Correct Answer)

-1

Two plane mirrors are inclined to each other such that a ray of light incident on the first mirror (M₁) and parallel to the second mirror (M₂) is finally reflected from the second mirror (M₂) parallel to the first mirror (M₁). The angle between the two mirrors will be :

45^o

60^o

75^o

90^o

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