Sunday, January 30, 2011

Spectrometer, Physics Practical for Standard 12

Spectrometer
AIM : -
To determine the prism-angle of a given prism.
(Keeping prism-table steady)
APPARATUS :-
A spectrometer, a source of light, a prism, a sprit-level and a magnifying glass. 

Spectrometer



 














Spectrometer Fixed Table


















Spectrometr on left


















Spectrometr on Right















Observations:
Spectrometer Observation table











Angle of prism

From the observations of window-X,
            2A = q1q2
                        \A =
From the observations of window-Y,
            2A = q1’  -  q2’
                        \A = 

It measures the color change. That gives the indication of the rate of the light reactions of the photosynthesis in the conditions of the experiment.

Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative energy as a function of its wavelength or frequency. Spectroscopic data is often represented by a spectrum, a plot of the response of interest as a function of wavelength or frequency.

Spectrometry and spectrography are terms used to refer to the measurement of radiation intensity as a function of wavelength and are often used to describe experimental spectroscopic methods. Spectral measurement devices are referred to as spectrometers, spectrophotometers, spectrographs or spectral analyzers.

Daily observations of color can be related to spectroscopy. Neon lighting is a direct application of atomic spectroscopy. Neon and other noble gases have characteristic emission colors, and neon lamps use electricity to excite these emissions. Inks, dyes and paints include chemical compounds selected for their spectral characteristics in order to generate specific colors and hues. A commonly encountered molecular spectrum is that of nitrogen dioxide. Gaseous nitrogen dioxide has a characteristic red absorption feature, and this gives air polluted with nitrogen dioxide a reddish brown color. Rayleigh scattering is a spectroscopic scattering phenomenon that accounts for the color of the sky.

Spectroscopic studies were central to the development of quantum mechanics and included Max Planck's explanation of blackbody radiation, Albert Einstein's explanation of the photoelectric effect and Niels Bohr's explanation of atomic structure and spectra. Spectroscopy is used in physical and analytical chemistry because atoms and molecules have unique spectra. These spectra can be interpreted to derive information about the atoms and molecules, and they can also be used to detect, identify and quantify chemicals. Spectroscopy is also used in astronomy and remote sensing. Most research telescopes have spectrographs. The measured spectra are used to determine the chemical composition and physical properties of astronomical objects (such as their temperature and velocity).

Thursday, January 27, 2011

Rate of Flow of Water,Physics practical For Standard 12

RATE OF FLOW OF WATER
AIM :-
Fill water in a cylinder vessel, connected with a capillary, upto some height ho. Allow water to flow through capillary in a controlled way and measure the height (h) of water, in vessel, at regular intervals (t) of time. Take ten such observations. Draw a graph of h / t and find the half-life of the flow of water.

Apparatus : A burette

A stand
A beaker
A stop-watch
A capillary of fine bore
A rubber tube
A pinch cock
Water




Rate of Flow of Water
Rate of Flow of water








































  Observation table 
Rate of Flow of water Observation table















Graph of Rate of Flow of Water

















Rate of Flow of Water Observation table












Graph of Rate of Flow of Water
 

Wednesday, January 26, 2011

A Simple Pendulum for standard 12 physics

A SIMPLE PENDULUM

AIM :-
To determine the value of g with the help of a simple pendulum.

PRECAUTIONS:
Understand clearly the functioning of the stop-clock.
The bob of the pendulum should not be given angular displacement more than 40.
The oscillations of the pendulum should be in one vertical plane only.
During oscillations the bob should not spin.
See that the bob does not collide with the table while oscillating.
The experiment should be performed at such a place where air current is slow. (Do not do the experiment near the window or a moving fan.)

APPARATUS : - A stand with a clamp,
                             a metallic bob,
                             a light string,
                             a meter rule,
                             a rubber cork with two pieces,
                             a vernier calliper
                             a stop-clock

Simple Pendulum Apparatus
                    















Simple Pendulum








































OBSERVATION TABLE
Simple pendulum observation table















Graph
Graph for Simple pendulum





















 

Simple pendulum Presentation


Sonometer for standard 12 Physics Practical

Sonometer

AIM :-
To study the relation between frequency and the length of a stretched string with the help of a sonometer.

PRECAUTIONS :-
The wire should be of uniform cross-section and there should not be any twist or bend in it.
The pulley should rotate without friction.
Put that much weight in the pan so that the deformation produced in the wire should not exceed the elastic limit.
The stem of the tuning fork, not its prongs, should be placed on the sonometer box or on the support.

Apparatus:-    A sonometer,
                       tuning forks ( of frequencies from 256 Hz – 512 Hz), 
                       a pan or a hanger of known weight,
                       four to five 500 gm weights,
                        a paper rider,
                       a rubber-pad and
                       a meter rule. 
Sonometer




         
          









OBSERVATION TABLE
Sonometer Observation table








Graph:-
Graph of Sonometer





















 

Sonometer Presentation

Frequency of Aelternating Current For Standard 12 Physics

Frequency of A.C.
AIM :-
To find the frequency of the alternating current with the help of a sonometer.
Sonometer Aim

PRECAUTIONS :-
It  is not advisable to use sonometer wire made of iron or any other magnetic materials.
The measurement of radius of the wire should be carried out precisely.
The transformer key should be switched off after every observation.
 The wire should be kept exactly in the middle between the magnetic poles.
      The wire should be of uniform cross-section and it should not have a twist or a bend.

Sonometer Precaution


Apparatus  :-         A sonometer,  
                                horse-shoe magnet,
                                a transformer,
                                a pan,
                                weights and
                                a micrometer screw.

Sonometer Apparatus

Sonometer Wiring diagaram
 
OBSERVATION TABLE

Sonometer Observation Table
  

Calculation:-
The linear density (i.e. mass per unit length) of the wire, m= prrr = . 
Calculation of √T/L.
The frequency of alternating current f = 1 / 2L √T / m = 1 / 2 √m * (average √T/L )



Sonometer 
(Frequency of Aulternating Current)
Presentation

Tuesday, January 25, 2011

Practical for standard 12

Dear Friends
In Old Version in Physics Practical there is 19 Physics practical.
which all practical i am going to upload for quick understanding about practical.
I am making this blog for standard 12 which is under uploading more practical so be with me you will get practical presentation download free.

Resonance tube Practical for Standard 12

RESONANCE TUBE Pr-19

AIM :-
To compare the frequencies of two tuning forks using a resonance tube and to find the end-correction. Repeat the experiment for two other tuning forks .
Find the lengths (l) of the resonating air columns for tuning forks of five different frequencies.
Draw a graph of 1 / f --

APPARATUS :-
A metallic tube open at both the ends (known as resonance tube),
a cylinder( of glass or metal) for filling water, a stand,
a meter rule,
a rubber-pad and tuning forks( two of known frequencies and two of unknown frequencies).

Apparatus for Resonance Tube


















































Resonance Tube Practical




































































































OBSERVATION TABLE :-

(1) Least count of the vernier callipers = cm
(2) Internal diameter of the resonance tube : d1 = cm; d2 = cm
 Average diameter d = cm

Observation table-1






















(1) f1 / f2 = l2 / l1
(2) f3 / f4 = l4 / l3
Observation table-2









Resonance Tube Graph

 

 Resonance tube Presentation

















Monday, January 24, 2011

Measurement of Resistance (Wheatstone's Bridge)

Practicle – 2
MEASUREMENT OF RESISTANCE ( WHEATSTONE’S BRIDGE)
AIM :-
You are given a Wheatstone bridge and other necessary instruments. Find the values of the unknown resistance Rx. Exchange the positions of unknown resistance and resistance box in the gaps of Wheatstone bridge and repeat the experiment.

PRINCIPLE :-
It works on the principle of balanced Wheatstone bridge.

APPARATUS:-    
Wheatstone-bridge (meter-bridge),
2 Volt Battery,
Rheostat,
Galvanometer,          
Jockey,
Key,
Resistance box(1 – 100  W),
Resistance coil.

Apparatus for Wheatstone's Bridge Practicle





 Precautions :-
  1. Make proper and tight connections.
  2. Keep the keys tightly closed in the resistance box.
  3. Adjust the value of resistance box so that null point is obtained between 40 cm and 60 cm.
  4. Do not slide the jokey continuously over the wire.
Note :-  Keep high resistance of rheostat in the beginning of each observation so that current is less and the galvanometer is not damaged. After getting approximate position of null point only decrease the resistance of rheostat.

(1) Condition :- Connect unknown resistance Rx between M – N.
Line Diagram For Wheatstone's Bridge
Wiring Diagram for Wheatstone’s Bridge.
Use this setup for carry out practical so it may be easy to understand.

Wiring Diagram for Wheatstone's Bridge
Measure L1 and L2 and note down in your Table.

(2) Condition :- Interchange unknown resistance Rx between P – Q.
In which interchange
Unknown  Resistance RX and Known Resistance Box RB.
Line  Diagram for Interchange RX And RB
Wiring Diagram for Wheatstone’s Bridge. (Condition-2)
In which interchange Unknown Resistance RX and Known Resistance Box RB.
Use this setup for carry out practical so it may be easy to understand.

Wiring Diagram for Interchange RX And RB


 
Conclusion :-
(1)   Unknown Resistance, Rx = …….. W
(2)    Unknown Resistance, Ry = ……...W

Law of Combinationof Resistors. (Wheatstone's Bridge),Video for std 8 to 12


Practical - 3
LAWS OF COMBINATION OF RESISTORS
( WHEATSTONE’S BRIDGE & POST OFFICE BOX )

AIM :-
You are given a Wheatstone Bridge and other necessary instruments. Find the values of the unknown resistance Rx and Ry . Now connect them in series and parallel respectively and measure their resultant resistances and test the laws of series and parallel connections.
PRINCIPLE :-     It works on the  principle of a balanced Wheatstone bridge. 

Apparatus :-   Wheatstone-bridge (meter-bridge),
                         2 Volt Battery,
                         Rheostat,
                        Galvanometer,
                        Jockey,
                        Key,
                        Resistance box(1 – 100 W),
                        Resistance coil.


Wheatstone Bridge Apparatus



(1)    Condition :- Connect unknown resistance Rx between  M – N.
Wheatstone Bridge line Diagram (Condition-1)
Wheatstone Bridge Wiring Diagram (Condition-1)


(2)    Condition :- Connect unknown resistance Ry between  M – N.
Wheatstone Bridge line Diagram (Condition-2)
Wheatstone Bridge Wiring Diagram (Condition-2)


(3)    Condition :- Connect unknown resistance in Series
Wheatstone Bridge line Diagram (Series connection)

Wheatstone Bridge Wiring  Diagram (Series connection)


(4)    Condition :- Connect unknown resistance in Parallel .
Wheatstone Bridge line Diagram (Parallel connection)


Wheatstone Bridge Wiring Diagram (Parallel connection)

                                                                                                                            

OBSERVATION TABLE
Wheatstone Bridge Observation table

CALCULATIONS :-
(1       (1) Series connection, R’s = Rx + Ry + …..W
(2)  Parallel connection, R’p = Rx Ry  /  Rx + Ry = ….W.


RESULT:-
(1) Unknown resistance, Rx = ….W, Ry = ….W

Wheatstone Bridge Observation table
 

CONCLUSION :
It is possible to verify the rules for series and parallel connections with the help of a meter bridge.


Precautions:-
(1) Make all connections tight.
(2)  Clean the ends of the connecting wire with a sand paper.
(3)  Plug keys of resistance box should be very tight.
(4)   Adjust the value of R from the resistance box such that null-point is obtained between 40 cm. and 60 cm.

Friday, January 21, 2011

Father


My Father


It would be interesting to know how Father's Day came into practice and celebrated worldwide with an equal sincerity and respect as any other significant holidays. Here's a short history on the holiday, and meaning of the different colors of roses to be worn that Day. You may even refer the page to others to share the information by clicking on the link given below.

About 4,000 years ago a young boy named Elmusu wished his Babylonian father good health and a long life by carving a Father's Day message on a card made out of clay. No one knows what happened to Elmesu or his father, but the tradition of having a special day honoring fathers has continued through the years in countries across the world.

The Countries, where the Catholic Church were of significant influence on the culture of the society, Father's Day is celebrated on St. Joseph's Day (March 19). However, a more secular celebration which is not associated with any religion is followed in recent times to highlight the increased diversity among people from all over the globe coexisting together in one place.

Father's Day is celebrated popularly on 3rd Sunday in June in many parts of the world. The idea for creating a day for children to honor their fathers began in Spokane, Washington. A woman by the name of thought of the idea for Father's Day while listening to a Mother's Day sermon in 1909. Having been raised by her father, Henry Jackson Smart, after her mother died, Sonora wanted her father to know how special he was to her. It was her father that made all the parental sacrifices and was, in the eyes of his daughter, a courageous, selfless, and loving man. Sonora's father was born in June, so she chose to hold the first in Spokane, Washington on the 19th of June, 1910.

In 1924 President Calvin Coolidge proclaimed the third Sunday in June as Father's Day. President Nixon, in 1972, established a permanent national observance of Father's Day to be held on the third Sunday of June. So Father's Day was born as a token of love and gratitude that a daughter cherishes for her beloved father. Roses are the Father's Day flowers: red to be worn for a living father and white if the father has died.