Ohm's law Experiment presentation with Audio and Video for std 12 Physics

Ohm's Law
AIM :-A voltmeter, a current meter, and an unknown resistance etc. are given to you. Prepare an appropriate circuit to verify Ohm’s law. With appropriate values of current and voltages, only with the help of calculations, determine the value of unknown resistance.
PRINCIPLE : Potential difference in a conductor produces electric current.
APPARATUS :-
A unknown resistance,
a voltmeter (0 - 10 V),
a milliammeter (0 - 500mA), a battery,
a rheostat,
a tap key,
connecting wires.

Internal Resistance of Primary Cell Experiment Potentiometer for std 12

Internal Resistance of Primary cell With the help of Potentiometer
EXPERIMENT :- 7
Internal resistance of primary cell
AIM :
To find the internal resistance of a primary cell, by calculation and from a graph, with the help of a potentiometer.
PRINCIPLE :
It works on the principle of potentiometer.
Apparatus:
A potentiometer having a long (~400 cm) resistive wire of uniform cross-section, a battery E of 3 to 4 V, a primary cell ( dry cell or Laclanche cell or a Daniel cell), two rheostats [ 0 – 25 W (Rh1) and 0 – 500 W (Rh2) ], a galvanometer, a R.B.(0 – 50 W), two simple keys and a jockey.

Internal Resistance of Primary Cell Experiment Apparatus

Internal Resistance Of Primary cell wiring diagram experiment

Internal Resistance Of Primary cell Observation table 

Internal Resistance Of Primary cell with graph 

Internal Resistance Of Primary cell Slop Experiment

Internal Resistance of Primary cell With Potentiometer Experiment Video

Copper voltameter Experiment for std 12 Physics with animation Video

AIM :-
Connect given copper voltameter in an appropriate circuit determine the electro chemical equivalent of copper.
PRINCIPLE :-
On passing electric current through CuSO4 solution, Cu+2 and SO-24 ions are separated or chemical effect of electric current.

APPARATUS :-
A copper voltameter,
6 V battery ( or D.C. Mains),
an ammeter,
a rheostat,
a simple key,
sand paper,
a stop-watch, balance,
weight box, etc.

Copper Voltameter Experiment  Apparatus

PRECAUTIONS
The cathode plate should be throughly cleaned after rubbing with sand paper.
Pass only that much current as is obtained from the calculation of the area of the immersed part of the cathode plate.
Use only a fresh solution of CuSo4. To prepare the solution dissolve about 25 g of CuSO4 crystals in 100 cm3 water. Add a few drops of sulphuric acid (H2SO4) to make it more conducting.
Hold the plate from its upper end so as to avoid touching its surface.
Cathode plate should be washed immediately after it is taken out of the solution.

Copper Voltameter  Experiment Line Diagram

Copper Voltameter  Wiring Diagram for Std 12 Experiment

PROCEDURE :-

1. To Cathode plate dip in clean water, and wash off all the CuSO4, solution sticking to it. Thereafter wash it again with tap water.
2. Hold it in the sunshine for some time till it dries out. Now find out its mass by Physical balance.

Observation table for Copper Voltameter

Copper Voltameter Experiment Observation Table

Copper Voltameter  Experiment Calculation

Copper Voltameter Experiment presentation Video.

Beautiful White material Monuments antique picture makes world nice

When rising in the morning
take time to pray
Wisest thing to do
before you begin the day

Ask God for His blessings
for what the day may bring
He'll guard and keep you
in the midst of everything
Your day will be brighter
sweet peace will abide
Seek the Lord
you won't be denied

When d sun sets...pray again and thank d Lord 4 all d graces we rcvd 4 d day...reflect and ask 4gvness from our sins...

Angle of Prism, Physics practical for the standard 12

REFRACTIVE INDEX OF PRISM

AIM:-

Determine with the help of pins, the angle of the given glass prism. Determine the values of angle of emergence and angle of deviation for four different values of angle of incidence. Hence prove that i + e = A +d.

PRINCIPLE :

Reflection and refraction of light.

PRECAUTIONS
 While marking the position of a prism with pencil, the prism should not be disturbed. 
A prism should be carefully put back exactly at the marked position. 
While pressing the heads of the pins for fixing them use metal coin or a hard object so that you do not hurt your palm. 
Do not press the pins very hard in the board otherwise it becomes difficult to remove them afterwards. 
See that the pins pushed in the board remain perpendicular to the board.

Angle of Prism 

Angle of Prism Conclusion

REFRACTIVE INDEX OF PRISM

AIM :-

Using pins with a given prism determine the angles of deviation for six different values of angle of incidence. Draw the graph of angle of deviation versus angle of incidence. Determine, from this the angle of minimum deviation and using following formula determine refractive index of material of the prism.

Angle of Prism Formula

Angle of prism, A = ……. .

Angle of Deviation measure

Angle of Deviation

Angle of Deviation Observation table  

Angle of Deviation Graph

Waves

" WAVES "

Wave
A wave is a disturbance that moves through a medium. The energy is transferred from one point to another without transport of any matter.

Frequency
It is the no. of waves passing through a point in the medium in one second (unit is Hertz).

Wave Length
The distance between two consecutive crests or two consecutive troughs is called wave length .
For the light waves, if the wave length is different, color of the light will be different.

Amplitude
The maximum displacement of the particle of the medium is called the amplitude of the wave.
When something vibrates it produces a sound. The energy of the the vibrations is passed on to the molecules in the surrounding air and makes them move. Thus the sound wave falls on the ear and the sound is heard. The stronger the vibrations, the longer the amplitudes and the louder the sounds.

Velocity
Wave velocity is the distance through which the wave moves in one seconds. Velocity of light is more than the velocity of sound, so in a thunderstorm, lightning will always be seen before the clap of thunder.

Waves Velocity

Waves are of two types

Transverse wave

If the displacement of the individual atoms  or Molecules is perpendicular to the direction of the wave, the wave is called a Transverse wave ( light wave ). 

Transverse wave

Longitudinal wave

If the displacement of  the individual atoms or molecules is parallel to the direction of the wave, the wave is called a Longitudinal wave  ( sound wave ).

 

 

 

 

 

Longitudinal wave

 

 

 

 

 

SOUND

STANDING WAVES

In a string fixed on both ends, when we strike or pluck at some point, waves propagate towards both ends & after reflection from the ends, overlap on each other to produce standing waves.

SOUND

STANDING WAVES

A violin string oscillates at a fundamental frequency.

 

Musical Instruments.

Musical Instruments.

Wind instruments.

Standing wave can also be produced in air columns. In organ pipes(open at both ends), bugle & flute (closed at one end) and in tabla & dholak (closed at both ends) standing waves on air column produces sound.

Wind Instruments.

Different tones are produced by the same instrument depending on the type of vibrations. Here the fundamental & first two overtones are shown for both open end & closed at one end air column vibrations.

The wavelength (l) of the sound wave depends on the length (L) of the air column. 

Wind instrument

String instruments.

The simplest form of string instrument is just a stretched string over a resonating body to amplify the sound.The standing waves produced in strucked string (piano) bowed string(violin)& plucked string (sitar & sarod) musical instruments produce a range of musical sounds.

Musical Instruments

AUDIBLE FREQUENCY RANGE

We can hear the sound if the frequency lies between 20 Hz. to 20 kHz. We hear low frequencies as low pitched and high frequencies as being high pitched.

AUDIBLE FREQUENCY RANGE

 

ULTRASONIC & SUBSONIC WAVES

Sounds above audible frequency are called ultrasonic and sounds below audible frequency are called infrasonic or subsonic sounds.

Elephants use very low-pitched sounds, below the level of human hearing ( subsonic sounds), that call other members of the heard over many miles. 

 

ULTRASONIC & SUBSONIC WAVES

APPLICATIONS OF ULTRASONIC SOUNDS

1. Sonar receptors in Bats &Whales:- The bats & whales send out some ultrasonic rays, which bounce back from the prey and are received by this system and they can locate the prey.

Sonar receptors in Bats &Whales

2. Application in Medicine :- Instead of stethoscope ultra-sonography is used as a tool by physicians, to scan abdominal, pelvic and cardiac areas. 

Application in Medicine

Ocean Depth

3. Ocean depth can be found by measuring the time between sending out an ultrasonic signal and receiving the echo reflected from the ocean bed.

Ocean depth

Detection of  MINERAL OIL

4. Oil layer reflects a  certain pattern of echoes which is detected by a seismograph.

Detection of  MINERAL OIL

Doppler effect

As the car moves away,wave fronts of its whistle take longer time to reach a listener, who hears a drop in pitch.- Long Wavelength -Low Frequency

As the car comes closer, sound wave fronts reach a listener ever more quickly and seem to rise in pitch.    Small Wavelength- High Frequency.

Doppler effect

Tuning Fork

When we strike a tuning fork, it will vibrate in a fixed frequency and a particular sound will be heard.

Tuning Fork

Sound waves produced by a tuning fork.

Acoustics of Auditorium

The clearest speech is heard in an auditorium when there is a time gap of 1/20^th of a second between the reflected rays and the direct rays, otherwise they will overlap and no sound can be heard clearly.

Acoustics of Auditorium

TEST YOURSELF

 

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 = q_1’  -  q_2’

                        \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).