Physics Class 10th PDF: Reflection, Refraction, Electricity, & Magnetism

Okay, here's the conversion of the images into a structured markdown format. ### Light: Reflection and Refraction **Relection of Light and Its Laws** * Reflection: bounce back of light when it hits any polished surface like a mirror * Laws: 1. $\angle i = \angle r$ 2. Incident ray,...

Okay, here's the conversion of the images into a structured markdown format. ### Light: Reflection and Refraction **Relection of Light and Its Laws** * Reflection: bounce back of light when it hits any polished surface like a mirror * Laws: 1. $\angle i = \angle r$ 2. Incident ray, reflected ray & normal lies in the same plane **Spherical Mirrors** * Concave/Converging * Description: A diagram of a concave mirror with the principal axis, pole (P), focus (F), and center of curvature (C) labeled. * Convex/Diverging * Description: A diagram of a convex mirror with the principal axis, pole (P), focus (F), and center of curvature (C) labeled. * Pole (P): midpoint on the mirror surface * Centre of curvature (C): centre of sphere from which mirror is cut * Principal axis: joins 'P' and 'C' * Radius of curvature: distance b/w 'P' and 'C' * Focal length (f): distance b/w 'P' and 'F' (Focus) NOTE: 'F' is centre of 'P' and 'C' $\implies R=2f$ **Image Formation: Rules** * At least 2 rays have to meet to form an image * If rays actually meet: Real image is formed, appear to meet: virtual image is formed 1. Rays parallel to principal axis, pass through 'F' 2. Rays passing through 'F' will be parallel to the principal axis 3. Rays passing through 'C' will reflect back along the same path **Image Formation by Concave Mirror** | Object Position | Image Position | Diagram | Nature of Image | | :-------------- | :-------------- | :------------------------------------------------------------------------------------------------------------------ | :------------------------------------------------------------------- | | At infinity | At 'F' | Description: Diagram showing parallel rays converging at F. | Real; inverted; point sized (highly diminished) | | Beyond 'C' | Between 'F'and 'C' | Description: Diagram showing object beyond C, image between F ans C |Real; inverted, and diminished | | At 'C' | At 'C' | Description: Diagram showing object and image at C | Real; inverted; same sized | | Between 'C' and 'F' | Beyond 'C'| Description: Diagram showing object between C and F with the image formed beyond C. | Real; inverted; bigger than the object | | At 'F'| At infinity | Description: Diagram showing rays becoming parallel after reflection | Real; inverted; highly enlarged | | Between 'P' and 'F' | Behind the mirror | Description: Diagram showing a virtual image formed behind the mirror.| Virtual; erect; enlarged; behind the mirror | NOTE: Real images are inverted; virtual ones are erect. **Image Formation by Convex Mirror** | Object Position | Image Position | Diagram | Nature of Image | | :------------------- | :-------------- | :-------------------------------------------------------------------------------- | :-------------------------------- | | At infinity | At 'F' | | Virtual; erect; point sized; behind the mirror | | Between infinity and 'P' | Between 'P' and 'F' | |Virtual; erect; diminished; behind the mirror| **Magnification** * Tells how large or small an image is w.r.t object * Magnification = $\frac{height\space of\space image}{height\space of\space object} = \frac{h_i}{h_o} = - \frac{v}{u}$ NOTE: m = +ve: virtual image **Uses of Mirrors** | Concave Mirror | Convex Mirror | | :------------------------------------------- | :-------------------------------------------------------------- | | Torch, headlights, shaving mirror, dentist mirror (enlarged image) | Real view mirrors (erect and small image and hence wide view) | **Spherical lenses** The image shows two diagrams of lenses: * Convex/Converging lens: labeled with C1, F1, optical center, F2, and C2. C1(2F1) & C2(2F2) * Concave/Diverging lens: labeled with C1, F1, optical center, F2, and C2.C1(2F1) & C2(2F2) C: centre of curvature; F: Principal focus; f: focal length **Image Formation: Rules** | | | | |:-------|:---------------| :--| | Image of three rules with convex lenses; rays bend when passing through the lenses |F1 O F2 | F2 F1 O| |Diagram of one rule with concave lens;| F1 O F2 | O F2 F1 | **Image Formation by Convex Lens** | Object Position | Image Position | Diagram | Nature of Image | | :-------------- | :-------------- | :-------------------------------------------- | :------------------------------------------- | | At infinity | At 'F2' | | Real; inverted; highly diminished (point sized) | | Beyond '2F1' | Between 'F2' and '2F2' | | Real; inverted and diminished | | At '2F1' | At '2F2' | |Real, inverted, same sized| | Between 'F1' & '2F1' | Beyond '2F2' ||Real; inverted; enlarged | |At 'F1'|At infinity|| Real; inverted; highly enlarged| |Between 'F1' and 'O'|Same side of lens as object | |Virtual, erect and enlarged| **Image Formation By Concave Lens** | Object Position | Image Position | Diagram | Nature of Image | | :-------------- | :------------------------------------------ | :--------------------------------------------- | :----------------------------------------------- | | At infinity | At 'F1' | | Virtual, erect and highly diminished (point sized) | **Important Notes** * Spherical Lens have 2 focus * Sign convention: all distances measured from 'O' * $\frac{1}{f} = \frac{1}{v} - \frac{1}{u} ;\ m = \frac{h_i}{h_o};\ $ signs same as mirror * Power of lens: Degree of convergence & divergence of a lens; SI unit: Dioptre (D) = m^-1; $P = \frac{1}{f}$ * Power: concave: -ve; convex: +ve **Refraction: Bending of Light** * It occurs due to change in medium which leads to change in speed of light * Refractive index (RI): tells about the density of a medium RI of 2nd medium w.r.t 1: $n_{12} = \frac{n_2}{n_1}$ RI ↑; density ↑; Speed of light *Absolute Refractive Index:* One medium is air. $n = 1$ $c = 3 \times 10^8 m/s$ * Laws of Refraction: 1. Incident ray, refracted ray & normal lie in the same plane 2. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for a given pair of media. * If we change $\angle i$ ; $\angle r$ also changes but ratio remained same **Refraction Through a Glass Slab** Description: Diagram illustrates refraction through a rectangular glass slab i - angle of incidence r - angle of refraction e - angle of emergence * Incident ray is parallel to the emergent ray * $\angle i = \angle e$ * Near point or Least Distance of Distinct Vision (LDDV): Minimum distance at which objects can be seen without strain (25 cm) ### Defects of Vision and Their Correction | Defects | Reasons | Corrections | | :----------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------- | | Myopia (Near sightedness) | Excessive curvature of eye lens (thick) and thus focal length decrease; image formed before the retina since eyeball enlarges | Use of concave lens | | Hypermetropia (Far sightedness) | Lens becomes thin and thus focal length increases; eyeball becomes small and thus image is made behind the retina | Use of convex lens | | Presbyopia Unable to see both near and far objects, Age related | Weakening of ciliary muscles and decreased flexibility of lens | Use of bifocal lenses| | Cataract| Lens become opaque/ milky which leads to partial or complete loss of vision| surgery| ### Refraction Through a Prism Prism is a glass which has a triangular & 3 rectangular surface: is a transparent refracting medium Description: Diagram of a prism showing the incident ray, refracted ray, emergent ray, angle of incidence ($i$), angle of refraction ($r$), angle of prism (A), and angle of deviation (D). Newton's Inverted Prism Experiment Due to refraction , Dispersion & Total internal reflection. Sun should be behind us & rainbow is formed in front ### Atmospheric Refraction Different layers close to earth have higher densities. **Tyndall Effect /Scattering of Light** * Scattering of light by heterogeneous colloidal particles *Colour of scattered light to the size of particle **Twinkling Of Stars** Stars are point of light Planets do not twinkle they are near to earth ### Domestic Electric Circuit * Safety measure * Discharges powerful surges to soil safely (avoid accidents) * Earth wire connected to the metallic part of appliances so that if current leaks, it can go down to earth * 1khw $= 3.6 xx 10^6$ which equals $= 1$ commercial unit of bijili Bill ### Electric power (P) Rate in which electrical energy is consumed watt Electrical energy e Supplied by the cells ### Magnetic Effects of Current * Area around is magmatic force **Fleming's left hand rule** Is where the conductor will move if moved. * Magmatic field can exert force