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<div style="position: absolute; left: -99999px;">Dispersion is the splitting up of white light (or a composite light) into its constituent colours. Dispersion occurs when light is passed through a prism. The dispersion is caused due to the the difference in the angle of deviation for different colours. In the case of a glass slab, the opposite sides are parallel and therefore different colors emerge parallel to each other and are seen simultaneously. Therefore, dispersion doesn’t occur in a glass slab. In a prism, the dispersion occurring at one face in enhanced by the refraction at the other face, but in a glass slab the dispersion occurring at one face is neutralized by refraction at the other face.

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Dispersion is the splitting up of white light (or a composite light) into its constituent colours.
Dispersion occurs when light is passed through a prism. The dispersion is caused due to the the difference in the angle of deviation for different colours.
In the case of a glass slab, the opposite sides are parallel and therefore different colors emerge parallel to each other and are seen simultaneously. Therefore, dispersion doesn’t occur in a glass slab.

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Unit and formula of electric polarisation

Posted by Shikha Verma 7 years ago

CBSE > Class 12 > Physics

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Nitika Neb 7 years ago

SI unit of measure is coulombs per square meter, and polarization density is represented by a vector P.

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In the half life period formula what is lambda?

Posted by Gagandeep Rathi 7 years ago

CBSE > Class 12 > Physics

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Shubham Sharma 7 years ago

Decay constant

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How. To make phy strong

Posted by Yash P. 7 years ago

CBSE > Class 12 > Physics

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[email protected] Pp 7 years ago

Practice daily Be it 4 hrs or half hour recap dosent matter

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The acceleration of a particle performing uniform circular motion on a circular path of radius 2m and completing 120 Revolution per minute is

Posted by Dharmveer Singh 7 years ago

CBSE > Class 12 > Physics

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Diagram and working principle of cyclotron

Posted by Sanju Singha 7 years ago

CBSE > Class 12 > Physics

4 answers

Nitika Neb 7 years ago

Bqv = (vm2 ) / r v /r = Bq / m = constant ...(1) The time taken to describe a semi-circle t = π r / v (2) Substituting equation (1) in (2), t = π m/ Bq .. (3) It is clear from equation (3) that the time taken by the ion to describe a semi-circle is independent of (i) the radius (r) of the path and (ii) the velocity (v) of the particle Hence, period of rotation T = 2t T = 2 π m / Bq = constant ...(4) So, in a uniform magnetic field, the ion traverses all the circles in exactly the same time. The frequency of rotation of the particle, v = 1 /T = Bq / 2 πm .. (5) If the high frequency oscillator is adjusted to produce oscillations of frequency as given in equation (5), resonance occurs. Cyclotron is used to accelerate protons, deutrons and α - particles.

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Nitika Neb 7 years ago

Construction It consists of a hollow metal cylinder divided into two sections D1 and D2 called Dees, enclosed in an evacuated chamber (Fig 3.21). The Dees are kept separated and a source of ions is placed at the centre in the gap between the Dees. They are placed between the pole pieces of a strong electromagnet. The magnetic field acts perpendicular to the plane of the Dees. The Dees are connected to a high frequency oscillator. Working: When a positive ion of charge q and mass m is emitted from the source, it is accelerated towards the Dee having a negative potential at that instant of time. Due to the normal magnetic field, the ion experiences magnetic lorentz force and moves in a circular path. By the time the ion arrives at the gap between the Dees, the polarity of the Dees gets reversed. Hence the particle is once again accelerated and moves into the other Dee with a greater velocity along a circle of greater radius. Thus the particle moves in a spiral path of increasing radius and when it comes near the edge, it is taken out with the help of a deflector plate (D.P). The particle with high energy is now allowed to hit the target T. When the particle moves along a circle of radius r with a velocity v, the magnetic Lorentz force provides the necessary centripetal force.

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Nitika Neb 7 years ago

Cyclotron- Principle, Construction, Working and Limitations of Cyclotron Cyclotron- Principle, Construction, Working and Limitations of Cyclotron Cyclotron is a device used to accelerate charged particles to high energies. It was devised by Lawrence. Cyclotron Cyclotron is a device used to accelerate charged particles to high energies. It was devised by Lawrence. Principle Cyclotron works on the principle that a charged particle moving normal to a magnetic field experiences magnetic lorentz force due to which the particle moves in a circular path

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Yash P. 7 years ago

Particle are acclerated to high energies by paasing it through moderate field and diagram from text

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Difination of threshold frequency

Posted by Pravind Kumar 7 years ago

CBSE > Class 12 > Physics

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Sanjay Singh 7 years ago

The minimum frequency required to an electron to emit from metal surface..

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please explain transistor as an amplifier

Posted by Vinayak Fupta 7 years ago

CBSE > Class 12 > Physics

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Yogita Ingle 7 years ago

Amplification is the process of linearly increasing the amplitude of an electrical signal. A transistor can act as an amplifier directly using the gain, b. When a transistor is biased in the active (linear) region, the BE junction has a low resistance due to forward bias and the BC junction has a high resistance due to reverse bias.

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Using Brewster law prove that when incident angle is equal to polarising angle then reflected ray is perpendicular to refracted ray?

Posted by Prashant Singh 7 years ago

CBSE > Class 12 > Physics

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What is young doubleslit

Posted by Sanat Patel Sanat Patel 7 years ago

CBSE > Class 12 > Physics

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Nitika Neb 7 years ago

The Young’s experiment shows that matter and energy can display both wave and particle characteristics. Purpose of double slit experiment is as follows:- In order to prove the wave nature of light. To explain the phenomenon of interference. Two coherent sources of light were taken in order to maintain the 0 or constant phase difference between the sources of light. Experimental set-up1:- Young took an ordinary source of light(S) such as light bulb. The light was made to pass through a very small slit S (which was comparable with the wavelength of light). The light coming from Source S was made to pass through two small slits S1 and S2 which were separated by a very small distance d. One screen was kept in front of these 2 sources. Observation1:- He observed alternate dark and light bands were formed on the screen. Setup 2:- Now he took 2 light bulbs i.e. 2 non coherent sources of light and placed a screen in front of them. Observation 2:- He observed there were no alternate bands of light formed on the screen. Conclusion:- When coherent sources of light were taken then the phenomenon of interference is taking place. When non-coherent sources were taken phenomenon of interference was not taking place. The source S illuminated the sources S1 and S2 as a result the light from S1 and S2 become coherent. S was the source of bothS1 and S2, therefore if there is any change in the phase of the source there will be change in the both sources also. Therefore both S1 and S2 will be always in phase with each other.

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What is young doubleslit experiment

Posted by Sanat Patel Sanat Patel 7 years ago

CBSE > Class 12 > Physics

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Nitika Neb 7 years ago

Calculation of path difference Let S1 and S2 are the sources and consider a point P where we have to calculate the intensity. Path difference = S2P-S1P Using Pythagoras theorem :- (S1P) 2 = D2 + (x-(d/2)) 2 equation(1) Where D=distance of the screen from 2 slits, x= position of the point where intensity has to be found. Similarly (S2P)2 = D2+ (x+(d/2)) 2 equation(2) Where d=distance between the 2 small slits. Subtracting (2) and (1) => (S2P)2 - (S1P) 2 =(x+(d/2)) 2 - (x-(d/2)) 2 On simplifying (S2P)2 - (S1P) 2 =2xd => (S2P+S1P)(S2P- S1P)=2xd =>(S2P- S1P) =(2xd)/(S2P+S1P) If d<<D ; x<<D(screen is placed quite far away from the slit arrangement) => (S2P+S1P) (are almost same as D). => S2P+S1P =2D Therefore (S2P- S1P) = (2xd)/(2D) Path difference =(xd)/(D)Equation(2) Observation:- Light from coherent sources produced alternate dark and bright bands on the screen placed some distance

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What is young doubleslit experiment derived expression for fringe width

Posted by Sanat Patel Sanat Patel 7 years ago

CBSE > Class 12 > Physics

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Write the expression for the generalised form of ampere's circuital law.Describe briefly how the concept of displacement current is explained through charging/discharging of a capacitor in an electric circuit.

Posted by Nimrah Ansari 7 years ago

CBSE > Class 12 > Physics

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How does the incidence angle in erecting prism is 45 degree

Posted by Shashikant Tripathi 7 years ago

CBSE > Class 12 > Physics

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Si unit of torque

Posted by Vibhor Nanda 7 years ago

CBSE > Class 12 > Physics

1 answers

Aryan Singh 7 years ago

N-m Newton metre

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Erecting prism

Posted by Shivi Mishra 7 years ago

CBSE > Class 12 > Physics

2 answers

Shashikant Tripathi 7 years ago

How the incidence angle become 45°

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Shashikant Tripathi 7 years ago

Me too

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An electron is accelerated through the potential difference V. Write the expression for its final speed, it was initially at rest .

Posted by Komal Pandey 7 years ago

CBSE > Class 12 > Physics

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Si unit of tourc

Posted by Vikash Meena 7 years ago

CBSE > Class 12 > Physics

2 answers

Rajat Dhull 7 years ago

I didnt read tourc in physics anywhere please tell me if u know

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Nitik Sangwan 7 years ago

The SI unit for torque is the ____ newton meter (N m or N·m)

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What is the total total focal length if concave lens and convex having same focal length of 20cm

Posted by Vijayalakshmi P 7 years ago

CBSE > Class 12 > Physics

1 answers

Vineet Kumar Gupta 7 years ago

It will behave like a plane mirror with focal length infinity

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Faradays 1st and 2nd law,in easy way?

Posted by Rafiya Ansari 7 years ago

CBSE > Class 12 > Physics

2 answers

Atul Rajak 7 years ago

1st law W directly proptional to Q 2nd law W1/w2 equals E1/E2 Where W is weight Q is charge E is equivalent mass

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Yogita Ingle 7 years ago

Faraday’s laws of Induction

First law: -

According to the first law an emf is induced in the circuit whenever the amount of magnetic flux linked with a circuit changes.
Current was induced because of magnetic flux, as there is some current in the circuit therefore there will be some emf flowing in the circuit.
Whenever the amount of magnetic flux linked with the circuit changes only at that time emf is induced.
The induced emf will be there till there is change in the flux.
When the magnet was moved then only there was change in the flux.
As the magnet is moving the number of magnetic lines crossing the area is also changing.
There is a change in the flux therefore there is induced emf.
If the magnet is not moving, there will be no change in the amount of magnetic flux so there is no induced current.

Second law: -

According to the second law the magnitude of the induced emf in a circuit is equal to the time rate of change of magnetic flux through the circuit.
Emf which is induced will depend upon rate at which the magnetic flux is changing.
Mathematically:-
- Let Φ₁ = flux at initial time t=0.
- Φ₂ = flux after time t.
- Rate of change of flux=(Φ₂ – Φ₁)/t =dΦ/dt

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Faradays laws of electromagnetic induction

Posted by Rafiya Ansari 7 years ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 7 years ago

Faraday discovered that when he moved a magnet near a wire a voltage was generated across it. If the magnet was held stationary no voltage was generated, the voltage only existed while the magnet was moving. We call this voltage the induced emf .

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Which paper will come in preliam 1

Posted by Aanchal Baurai 7 years ago

CBSE > Class 12 > Physics

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What are the properties of conduction band

Posted by Suman Kumari 7 years ago

CBSE > Class 12 > Physics

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Manish Yadav 7 years ago

A condiction band is a imaginary band qhich consists of free or mobile electrons which are responsible for conduction

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What is x ray give one us

Posted by Anurag Dhiman 7 years ago

CBSE > Class 12 > Physics

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Nitika Neb 7 years ago

a kind of light that makes it possible to see inside solid objects, for example the human body, so that they can be examined and a photograph of them can be made Use of x ray is to locate cracks ,fractures in human skeleton system

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Importance of radial magnetic field in galvanometer

Posted by Sahabaz Alam 7 years ago

CBSE > Class 12 > Physics

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Rahul Sehlangia 7 years ago

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Gaurav Seth 7 years ago

Importance and production of radial magnetic field :

In a radial magnetic field, magnetic torque remains maximum for all positions of the coils.
It is produced due to cylindrical pole pieces and soft iron core.In radial magnetic field , the plane of the coil is always parallel to plane of the magnetic field and area vector of the coil is perpendicular to magnetic field . It always exerts maximum torque on the coil.

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What is the SI unit of energy

Posted by Ansh Tiwari 7 years ago

CBSE > Class 12 > Physics

2 answers

Rajat Dhull 7 years ago

Most difficult question hai ye to

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Ansh Tiwari 7 years ago

Joule

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Disadvantages of cyclotron

Posted by Atharva Mate 7 years ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 7 years ago

LIMITATIONS OF CYCLOTRON

Only when the speed of the circulating ion is less than 'c' the speed of light, we find the frequency of revolution to be independent of its speed.
At higher speeds, the mass of the ion will increase and this changes the time period of the ion revolution. This results in the ion lagging behind the electric field and it eventually loses by collisions against the walls of the dees.