NCERT Solutions For Class 12 Physics Chapter 9: Ray Optics and Optical Instruments

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NCERT Solutions for Class 12 Physics Chapter 9 Ray Optics and Optical Instruments are provided in this article. Optics helps us study the properties and behaviour of light. In Ray Optics, the light travels in a straight line stating that there is an image for each and every object. The optical devices made utilising reflecting and refracting properties of lenses, mirrors and prisms known as Optical instruments.

Class 12 Physics Chapter 9 is a part of Unit 6 Optics which along with Unit 5 Electromagnetic Waves has a weightage of 18 marks in the CBSE Class 12 Board exam. The NCERT Solutions for Class 12 Physics Chapter 9 covers concepts of refraction, Snell’s Law, and total internal reflection

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NCERT Solutions for Class 12 Physics Chapter 9

NCERT Solutions

Class 12 Physics Chapter 9 – Important Topics Covered

Ray Optics is the branch of physics that deals with the behaviour of light as a ray which travels in a straight line.

Light always travels in a straight line. It does not require any medium to travel

Reflection is the phenomenon wherein light changes its path without any change in the medium.

Laws of Reflection

The angle of incidence, represented as i is equal to the angle of reflection, represented as r.
∠i = ∠r.
The incident ray, the reflected ray and the normal to the reflecting surface at the incidence point, all lie in the same plane.

The mirror formula represents a relation between the focal length of the mirror and the distances of objects and images from the mirror.

${1 \over v} + {1 \over u} = {1 \over f} $

Linear Magnification: The ratio of the size of the image that is formed by a spherical mirror I to the size of the object O is known as linear magnification.

$m={I \over O}={-v \over u}$

Refraction is the phenomenon of change in the path of light as it goes from one medium to another.

Laws of Refraction

The incident ray, refracted ray and the normal to the refracting surface at the point of incidence, all lie in the same plane.
The ratio of the sin of the angle of incidence to the sin of the angle of refraction is constant for any two given mediums. This constant is the relative refractive index.

n = sin i/sin r (Snell’s law)

where, n is the refractive index of the second medium when first medium is air.

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CBSE CLASS XII Related Questions

1.
In a region, the electric potential varies as $V = 10 - 50x$, where $V$ is in volts and $x$ is in meters. The electric field in the region is

$10\ \text{N/C}$ along $+x$
$10\ \text{N/C}$ along $-x$
$50\ \text{N/C}$ along $+x$
$50\ \text{N/C}$ along $-x$

View Solution

2.
A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is (i) $\sqrt{2}$, and (ii) $\sqrt{3}$.

View Solution

3.
Consider the nuclear reaction $ X \to Y + Z $. Let $ M_x $, $ M_y $, and $ M_z $ be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

$ (M_x - M_z)<M_y $
$ (M_x - M_y)<M_z $
$ M_x>(M_y + M_z) $
$ M_x<(M_y + M_z) $

View Solution

4.
A wire of length $L$ is bent round into (i) a square coil having $N$ turns and (ii) a circular coil having $N$ turns. The coil in both cases is free to turn about a vertical axis coinciding with the plane of the coil, in a uniform, horizontal magnetic field and carry the same currents. Find the ratio of the maximum value of the torque acting on the square coil to that on the circular coil.

View Solution

5.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

View Solution

6.
A current of $4.0\,\text{A}$ flows through a wire of length $1\,\text{m}$ and cross-sectional area $1.0\,\text{mm}^2$, when a potential difference of $2\,\text{V}$ is applied across its ends. Calculate the resistivity of the material of the wire.

View Solution

NCERT Solutions For Class 12 Physics Chapter 9: Ray Optics and Optical Instruments

NCERT Solutions for Class 12 Physics Chapter 9

Class 12 Physics Chapter 9 – Important Topics Covered

CBSE CLASS XII Related Questions

1.
In a region, the electric potential varies as \(V = 10 - 50x\), where \(V\) is in volts and \(x\) is in meters. The electric field in the region is

2.
A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is (i) $\sqrt{2}$, and (ii) $\sqrt{3}$.

3.
Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

5.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

6.
A current of \(4.0\,\text{A}\) flows through a wire of length \(1\,\text{m}\) and cross-sectional area \(1.0\,\text{mm}^2\), when a potential difference of \(2\,\text{V}\) is applied across its ends. Calculate the resistivity of the material of the wire.

Similar Physics Concepts

Comments

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NCERT Solutions For Class 12 Physics Chapter 9: Ray Optics and Optical Instruments

NCERT Solutions for Class 12 Physics Chapter 9

Class 12 Physics Chapter 9 – Important Topics Covered

CBSE CLASS XII Related Questions

1.In a region, the electric potential varies as \(V = 10 - 50x\), where \(V\) is in volts and \(x\) is in meters. The electric field in the region is

2.A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is (i) $\sqrt{2}$, and (ii) $\sqrt{3}$.

3.Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

5.Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

6.A current of \(4.0\,\text{A}\) flows through a wire of length \(1\,\text{m}\) and cross-sectional area \(1.0\,\text{mm}^2\), when a potential difference of \(2\,\text{V}\) is applied across its ends. Calculate the resistivity of the material of the wire.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
In a region, the electric potential varies as \(V = 10 - 50x\), where \(V\) is in volts and \(x\) is in meters. The electric field in the region is

2.
A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is (i) $\sqrt{2}$, and (ii) $\sqrt{3}$.

3.
Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

5.
Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.

6.
A current of \(4.0\,\text{A}\) flows through a wire of length \(1\,\text{m}\) and cross-sectional area \(1.0\,\text{mm}^2\), when a potential difference of \(2\,\text{V}\) is applied across its ends. Calculate the resistivity of the material of the wire.