Class-X Physics

(1)

• Electricity

Concept Maps

Class X

• Magnetic Effect of Current

Physics

• Refraction

• Spherical Lens

• Spherical Mirror

• Human Eye

• Non Conventional Sources

• Conventional Sources

(2)

ELECTRICITY

Ohm's Law Electric Potential Heating effect of current Resistance Electric current System of resistances Circuit Diagram Power Series Parallel R = R +s 1 R +R + ...2 3 Rp 1 R1 1 R2 1 R3 1 = + + Amount of heat H = VIt = I Rt = (V /R)t2 2 Heat in to work Electric heater Fuse Bulb Rate of flow of electric charges Unit:ampere Formula:I=Q/t Measurement: by ammeter At constant temperature V = IR Unit:ohm W Formula:R= L/Ar Dependence: •temperature •material •Length •area Where = resistivtiy depends only on temperature and material r Defination: Electric energy per unit time

Formula: P=I R=2 Unit : watt(W) V2 =VI R Commercial unit: KWH=3.6×10 J6 +– Cell Resistor Voltmeter Connected in parallel with the resistor Connecting Wire

Ammeter in series with

the circuit A V Close Open Switch: Bulb: G Galvanometer: Parallel combination of resistances Unit:volt(V) Formula:V=W/Q Measurement: by voltmeter Definition: Work done to move a unit charge A V House hold electricity L N L N E Local Earthing Company Fuse or Pole Fuse kWh Meter Main Fuse

Double Pole Switch or Main Switch

(3)

MAGNETIC

EFFECT OF

CURRENT

Electromagnetic induction Field lines Magnet

Field due to current

carrying conductor From north to south pole

in form of closed curve

Straight conductor

Direction of the field Field strengthµcurrent

µ Properties

Force on current carrying conductor in magnetic field

Circular loop Solenoid

Field strength depends on the closeness of the field lines Tangential drawn at any point gives the direction of field

distance between magnet and conductor

1

•Right hand thumb rule •Maxwell's screw rule Polarity of coil:

Clock rule

Field strengthµcurrent µ 1 distance 1 µNumbers of turns Field strength µNumbers of turns Current

Nature of core material µ

µ

•Fleming left hand rule •Right hand palm rule Direction of the force

Magnitude: F=IlBsinq

Due to change in magnetic flux current induces

•Fleming right hand rule •Lenz rule

Direction of the emf

B= 2r N×mo×I B= 2 rp N×mo×I Artificial magnet Natural magnet Temparory magnet Permanent magnet Types Attractive property Directional property Pole always exist in pair •Same pole repel each other •opposite pole attract each other

A

B

Cardboard Current

(4)

SPHERICAL LENS

Convex_lens Concave lens Power of lens Sign convention Lens formula Magnification (m)

m = positive= virtual & erect image

nega real inverted

m = tive= & image

f 1 u 1 v 1 ! " v = image distance u = object distance f = focal length f 1 P! •Degree of convergence or divergence • Measured in diopter(D) Same as mirrors Image formation Ray diagram Image formation Ray diagram Position of the object Position of the image Size of the image Nature of the image At infinity At F Highly diminished Virtual and erect Between

O and#

Between

O and F Diminished Virtual and erect

Position of the object Position of the image Size of the image Nature of the image At infinity At the focus F Highly diminished Real and inverted Beyond 2F Between

F and 2F Diminished Real and inverted At 2F At 2F Same size Real and inverted Between

F and 2F Beyond 2F Magnified Real and inverted At F At infinity Highly magnified Real and inverted Between

O and F

On the side of

the object Magnified Virtual and erect

P2 P1 C1 C2 R1 R2 Principal axis Radius of Curvature Centre of Curvature Optical Centre (a) O ce tan dis object ce tan dis age Im object of Height image of Height ! E O A B' F A' 2F F 2F B B' F B A' E O F G A 2F

(5)

REFRACTION

Through glass slab Through atmosphere Colour Through prism Scattering of light Tyndall effect Blue colour of sky

Colour of sun at sunrise & sunset

Dispersion of light due to particles in the atmosphere The fine particles in air

reflect blue colour

Hence for an astronaut outside

atmosphere sky appears dark instead of blue Less blue scattered Sun nearly overheated Observer Light travels longer distance

Blue scattered away Sun appears reddish

Sun near horizon R O Y G B V A I PRISM (P)2 SCREEN PRISM (P)₁ A R R v v A Dispersion Recombination Light travels shorter distance Actual Position of Sun Apparent Position of Sun S S Observer Earth Atmosphere Horizon Twinkling of stars

•Planets are much closer to earth

•Planets are a collection of large number of point sized source of light

•total variation in the amount of light entering our eye average to zero Laws of refraction r i sin sin =1$2 • •incident,refracted ray & normall lie in same plane 2 1$ 2 1 v v 2 1 % % 1 2 $ $ = = = 2 1$ is refractive index of med.2 wrt medium 1 depth Apparent depth al Re 2 1$ =

(6)

SPHERICAL

MIRROR

Convex mirror Concave mirror Power & magnification Sign convention mirror formula Laws of reflection v = image distance u = object distance f = focal length Measured in diopter(D) Image formation Ray diagram Image formation Ray diagram f 1 u 1 v 1 ! & P B A Incident Light C B' A' F B P A Incident Light C B' A' F Position of the object Position of the image Size of the image Nature of the image

At infinity At the focus F Highly diminished Real and inverted Beyond C Between F and C Diminished Real and inverted

At C At C Same size Real and

inverted Between

F and C Beyond C Magnified

Real and inverted At F At infinity Highly magnified Real and inverted Between optical centre and F Behind the mirror Magnified Virtual and erect Position of the object Position of the image Size of the image Nature of the image At infinity At F Highly diminished Virtual and erect Between

O and#

Between

O and F Diminished Virtual and erect

Centre of curvature Principal axis Aperture Aperture C Light gets reflected from

concave surface Principal axis Light reflect from convex surface Pole Silver coating Radius of curvature Radius of curvature Concave mirror Convex mirror C Centre of curvature Pole Silver coating f 1 P!" 1 2 h h u v m!" !

•Angle of incidence= angle of reflection •incident,refracted ray & normal lie in

same plane

m = positive

= virtual & erect image nega real inverted m = tive= & image Uses:torches, search light Uses:Rear view mirror

(7)

HUMAN

EYE

Structure & working

iris

lens

cornea

pupil

sclera

choroid

retina

opticnerve

ciliary muscels

muscles

aqueous humour

vitreous humour

Image formed Electrical signals sent to brain via optic nerves

Has enormous light sensitive cells

Get activated upon illumination and generate electrical signals

To change focal length of lens Forms an inverted

real image on retina Fine focal adjustments

Controls amount of light Light enters through cornea

Eye ball Sphere diameter

2.3 cm Controls size of pupil

Dark muscular diaphragm

Defects

Presbyopia Caused due to old age

Correction:Bifocal lens with both

concave and convex lens Accomodation

•Ability to adjust focal length its self •Can't decreased below certain minimum limit

•The farthest point for normal eye-infinity •The least distance for normal eye-25 cm Cataract

•For old people lens becomes milky & cloudy •Lens restored by cataract surgery

Myopia Hypermetropia 25 cm Short eyeball (a) Normal near point 25 cm N N' Near point of defective eye (b) N 25 cm N N' Near point of defective eye (c)

(8)

NON C0NVENTIONAL SOURCES Geo thermal energy Energy from sea Solar energy Nuclear energy Tidal energy Wave energy Ocean thermal Due to difference in temperature of layers

Kinetic energy of waves into electrical energy

Due to difference in sea levels Uses : Solar cell,

Solar cooker, etc.

Source is molten trapped in hotspots

Nuclear fission: Nucleus of heavy atom bombarded with low energy neutrons

Ammonia Vapours Generator Turbine Heat Exchanger (Evaporator) Warm Sea Water Pump Liquid Ammonia Heat Exchanger (Condenser) Discharge Cold Sea water

(9)

C0NVENTIONAL SOURCES Hydro Power Plant Bio Gas Plant wind energy Fossil Fuels Source is scurry used as manure, smokeless, 75% is methane High maintenance

and needs high wind speed but renewablesource

Source is molten trapped in hotspots

Nuclear fission: Nucleus of heavy atom bombarded with low energy neutrons

Mixing Tank Ground level Overflow Tank

Dung and water mixture

Water Slurry of cattle dung and water

Slab cover Gas Control Valve

Outlet for Biogas

Biogas Slab Cover Dome Spent Slurry Outlet Tank Inlet Tank Digestor