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 = q1 -  q2
                        \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