NEET Physics PYQ – Ray Optics and Optical Instruments Chapter Wise

Q 1 :
$ε_{0}$ and $μ_{0}$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $2 ε_{0}$ and $1.5 μ_{0}$ respectively, the refractive index of the medium will nearly be [2023]

$\sqrt{2}$
$\sqrt{3}$
3
2

1

2

3

4

(2)

$μ = \frac{c}{v} = \frac{\frac{1}{\sqrt{μ_{0} ε_{0}}}}{\frac{1}{\sqrt{1.5 μ_{0} \times 2 ε_{0}}}} = \sqrt{3}$

Q 2 :
A light ray falls on a glass surface of refractive index $\sqrt{3}$ , at an angle 60°. The angle between the refracted and reflected rays would be [2022]

30°
60°
90°
120°

1

2

3

4

(3)

[IMAGE 268]

The refractive index of glass, $μ = \sqrt{3}$

Angle of incidence = $60 °$

Let $' r'$ be the angle of refraction.

Now, applying Snell's law

$1 \times \sin 60 ° = μ \times \sin r$

$\Rightarrow \frac{\sqrt{3}}{2} = \sqrt{3} \times \sin r$

$\Rightarrow \sin r = \frac{1}{2}$

$\Rightarrow r = 30 °$

Let $θ_{1} + θ_{2},$ be the angle between reflected ray and refracted ray.

Hence, from the figure we can say that

$θ_{1} + θ_{2} = 60 ° + 30 ° = 90 °$

Q 3 :
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is [2016]

8
10
12
16

1

2

3

4

(3)

[IMAGE 269]

Here $μ = 1.5$

$l =$ length of the slab

$x =$ position of air bubble from one side

As per question, total apparent length of slab = 5 + 3

$or \frac{x}{μ} + \frac{(l - x)}{μ} = 8 or \frac{l}{μ} = 8$ $∴$ $l = 8 μ = 8 \times 1.5 = 12$ $cm$

Topic Question Set

Q 1 :
$ε_{0}$ and $μ_{0}$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $2 ε_{0}$ and $1.5 μ_{0}$ respectively, the refractive index of the medium will nearly be [2023]

Q 2 :
A light ray falls on a glass surface of refractive index $\sqrt{3}$ , at an angle 60°. The angle between the refracted and reflected rays would be [2022]

Q 3 :
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is [2016]

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Topic Question Set

Q 1 : ε0 and μ0 are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are 2ε0 and 1.5μ0 respectively, the refractive index of the medium will nearly be [2023]

Q 2 : A light ray falls on a glass surface of refractive index 3, at an angle 60°. The angle between the refracted and reflected rays would be [2022]

Q 3 : An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is [2016]

Want Us to Email you About Special Offers & Updates?

Q 1 :
$ε_{0}$ and $μ_{0}$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $2 ε_{0}$ and $1.5 μ_{0}$ respectively, the refractive index of the medium will nearly be [2023]

Q 2 :
A light ray falls on a glass surface of refractive index $\sqrt{3}$ , at an angle 60°. The angle between the refracted and reflected rays would be [2022]

Q 3 :
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is [2016]