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.
The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

\( \frac{q}{4 \pi \epsilon_0 l^2} \) pointing along MA
\( \frac{q}{\pi \epsilon_0 l^2} \) pointing along AM
\( \frac{q}{2 \pi \epsilon_0 l^2} \) pointing along AM
Zero

View Solution

2.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

5 V
3.5 V
2.5 V
Zero V

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3.
Two parallel plate capacitors X and Y are connected in series to a 6 V battery. They have the same plate area and same plate separation but capacitor X has air between its plates, whereas capacitor Y contains a material of dielectric constant 4. Calculate the capacitances of X and Y, if the equivalent capacitance of the combination of X and Y is \( 4 \, \mu\text{F} \). Calculate the potential difference across the plates of X and Y.

View Solution

4.
Write any two features of nuclear forces.

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5.
Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

(i) and (iii) only
(iii) and (iv) only
(i), (iii) and (iv) only
All of them

View Solution

6.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

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.
The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

2.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4.
Write any two features of nuclear forces.

5.
Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

6.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

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.The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

2.A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4. Write any two features of nuclear forces.

5.Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

6. Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
The figure shows three point charges kept at the vertices of triangle ABC. The net electric field, due to this system of charges, at the midpoint M of base BC will be:

2.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

4.
Write any two features of nuclear forces.

5.
Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

6.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.