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How is area of loop decrease and rectangular loop remain constant moving in uniform magnetic field

Posted by Pirtpal Singh 7 years ago

1 answers

When the loop moves out of magnetic field its area is decreased as the part of loop present in the magnetic field is less than that which is present before

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Is arihant 10 year sufficient for boards???

Posted by Vrishika Arora 7 years ago

CBSE > Class 12 > Physics

1 answers

Shivam Vashist 7 years ago

Yes but along with ncert intext questions

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What is the Si unirs of polarization vector P

Posted by Pankaj Singh 7 years ago

CBSE > Class 12 > Physics

1 answers

Nitika Neb 7 years ago

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

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What is rhe SI units of the polarization vector P

Posted by Pankaj Singh 7 years ago

CBSE > Class 12 > Physics

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Vidyanand Gupta 7 years ago

si unit of measure is coloumbs per square cm and vector is represented by P

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Describe briefly how wave theory of light cannot explain photoelectric effect?

Posted by Ritik Pawar 7 years ago

CBSE > Class 12 > Physics

1 answers

Sahana Sankar 7 years ago

Acc to wave theory, light is an em wave consisting of electric and magnetic fields with continuous distribution of energy over the region over which the wave extends. This wave picture of light could not explain the basic features of light as given below. 1. Acc to wave theory, when a wavefront of light strikes the metal surface, the free electrons at the sirface absorb the radiant energy continuously. Greater the intensity of incident radiation, greater are the amplitude of electric and magnetic fields and greater is the energy density of wave. Hence higher intensity should liberate photo electrons with greater kinetic energy. But this is contrary to the experimental result that the maximum kinetic ecmnergy of the photoelectorns does not depend on intensity of incident radiation. 2. No matter what the frequency of incident radiation is, a light wave of sufficient intensity (over a sufficient time) should be able to impart enough energy required to ehect the electron from the metal surface. Thus wave theory fails to explain the existence of threshold frequency. 3. The energy of light wave is smoothly and evenly distributed across its advancing wavefront. Each electron intercepts an insignificantly small amount of this energy and so it should require a finite time to escape from the metal surface. But actually the emission is almost instantaneous.

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A charged particle enter a magnetic field with its initial velocity making an angle 45° with the direction of magnetic field. what will be the nature of the path followed by the particle???

Posted by Suhani Rana? 7 years ago

CBSE > Class 12 > Physics

2 answers

Vidyanand Gupta 7 years ago

helical shape

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Ravi Kumar 7 years ago

Helical

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Two charges +Q and -Q are located at points (a,0) and(-3a,0). what is electric flux due to these charges through a sphere of radius 2a with its centre at the origin???

Posted by Suhani Rana? 7 years ago

CBSE > Class 12 > Physics

3 answers

Priyanka Kumari 7 years ago

Q/€o

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Vidyanand Gupta 7 years ago

q/€o

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Shubham Sharma 7 years ago

Q/£°

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Q.How does amphere maxwell law explain the flow of current through a capacitor when it is being charge by a variable frequency AC source. Write the expression for the displacement current I in terms of the rate of change in electric flux.

Posted by Xyz B 7 years ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 7 years ago

During charging, electric flux between the plates of capacitor keeps on
changing; this results in the production of a displacement current
between the plates.
Expression for the displacement current

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Distinguish b/w unpolarised light and linearly polarized light.How does one get linearly polarised light with the help of polaroid?

Posted by Xyz B 7 years ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 7 years ago

In a beam of unpolarized light, the vibrations of light vectors are in all directions in a plane perpendicular to the direction
of propagation.

In the linearly polarised light, the vibrations of light take place in a particular direction, perpendicular to the direction of
wave motion.
Polarized light can be distinguished, from unpolarized light, when it is allowed to pass through a Polaroid. Polarized light
does can show the change in its intensity, on passing through a Polaroid; intensity remains same in case of unpolarized
light.

When the unpolarised light wave is incident on a polaroid, then the electric vectors along the direction of its aligned
molecules, get absorbed; the electric vector, oscillating along a direction perpendicular to the aligned molecules, pass
through. This light is called linearly polarized light.

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What is objective question is it mcq

Posted by Aryan Singh 7 years ago

CBSE > Class 12 > Physics

1 answers

H I T E S H 7 years ago

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Define Coulmb's law.?

Posted by Aerik Vishnu 7 years ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 7 years ago

Coulomb’s law states that Force exerted between two point charges:

Is inversely proportional to square of the distance between these charges and
Is directly proportional to product of magnitude of the two charges
Acts along the line joining the two point charges.

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What is magnetic suspectibiliry

Posted by Mubarakpur Kotwa Chayal 7 years ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 7 years ago

Magnetic susceptibility in electromagnetism is defined as the measure of how much a material will be magnetized in an applied magnetic field. It is denoted by χ.

The mathematical definition of magnetic susceptibility is the ratio of magnetization to applied magnetizing field intensity. This is a dimensionless quantity.

Where,

χ: magnetic susceptibility

M: magnetization

H: field intensity

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A concave lens of refractive index 1.5 is immersed in a medium of refractive index 1.65. What is the nature of the lens.

Posted by Shikhar Kumar Gupta 7 years ago

CBSE > Class 12 > Physics

2 answers

Khushi Verma 7 years ago

If refractive index of lens is greater than medium than its nature is changed, but if it is lesser than that of medium than it is same

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Gaurav Seth 7 years ago

If refractive index of medium is greater then refractive index of lens then lens gain opposite nature . e.g when lens is initially cancave then after submerge in medium lens show convex nature and voce-versa .
reason :-
we know ,
1/v. - 1/u. = (d - 1){ 1/ R 1 - 1/ R 2}
d is the relative refractive index of system.
if initially (d -1){ 1/R 1 - 1/R 2} is positive

after submerge ,
d=1.5/1.65 <1 so, ( d-1 ) < 0
it means
(d - 1){ 1/R 1 - 1/R 2 } will be negative .
so,
lens will be convex

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A biconcave lens made of a transparent material of refractive index 1.25 is immersed in water of refractive index 1.33 . Will the lens behave as converging or a diverging lens? Give reason.

Posted by Sahana Sankar 7 years ago

CBSE > Class 12 > Physics

2 answers

Vidyanand Gupta 7 years ago

it is convex lens

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Rahul Prajapati 7 years ago

convex lens

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light falls fromto glass (n=1.5)to air. find the angle of incidence from which the angle of deviation is 90°

Posted by Rohan Kumar 8 7 years ago

CBSE > Class 12 > Physics

0 answers

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Important derivation for board which is frequently asked

Posted by Jeevita Jennie 7 years ago

CBSE > Class 12 > Physics

0 answers

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Important derivation for Physics

Posted by Amar Kumar 7 years ago

CBSE > Class 12 > Physics

0 answers

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Important question

Posted by Ram Krishna Pal 7 years ago

CBSE > Class 12 > Physics

0 answers

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Is the question paper pattern has been changed or not??? What does the 25% objective included in question paper???

Posted by Kishu Raj 7 years ago

CBSE > Class 12 > Physics

0 answers

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Borsh law

Posted by Ashish Roy 7 years ago

CBSE > Class 12 > Physics

0 answers

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using gauss law obtain the electric flux due ti a point charge 'q' enclosedin a cube of side 'a'

Posted by A B 7 years ago

CBSE > Class 12 > Physics

2 answers

Geetanjali Tevathiya 7 years ago

q/6€o is from any face but total is q/€o

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Kishu Raj 7 years ago

q/6€

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If the angle between the pass axes of a polariser and analyzer is 45°. Write the ratio of the intensity of original light and the transmitted light after passing through the analyzer.

Posted by Aryan Raj 7 years ago

CBSE > Class 12 > Physics

1 answers

Sahana Sankar 7 years ago

1/2

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For how many marks will we get problems in exam

Posted by Sahana Sankar 7 years ago

CBSE > Class 12 > Physics

1 answers

Pratham Kaushik 7 years ago

1,2,3,5 questions is asked in exam

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Different between conductor and insulator and semiconductor

Posted by Richa Singh 7 years ago

CBSE > Class 12 > Physics

2 answers

Rohan Sharma 7 years ago

CHARACTERISTICS CONDUCTOR SEMI-CONDUCTOR INSULATOR Conductivity High Moderate Low Resistivity Low Moderate Very High Forbidden gap No forbidden gap Small forbidden gap Large forbidden gap Temperature coefficient Positive Negative Negative Conduction Large number of electrons for conduction Very small number of electrons for conduction Moderate number of electrons for conduction Conductivity value Very high 10-7mho/m Between those of conductors and insulators i.e. 10-7mho/m to 10-13mho/m Negligible like 10-13mho/m Resistivity value Negligible; less than 10-5 Ω-m Between those of conductors and insulators i.e. 10-5 Ω-m to 105 Ω-m Very high; more than 105 Ω-m Current flow Due to free electrons Due to holes and free electrons Due to negligible free electrons Number of current carriers at normal temperature Very high Low Negligible Band overlap Both conduction and valence bands are overlapped. Both bands are separated by an energy gap of 1.1eV Both bands are separated by an energy gap of 6eV to 10eV 0 Kelvin Behavior Acts like a superconductor Acts like an insulator Acts like an insulator Formation Formed by mettalic bonding Formed by covalent bonding Formed by ionic bonding Valence Electrons One valence electron in outermost shell Four valence electron in outermost shell Eight valence electron in outermost shell Examples Copper, mercury, aluminum, silver Germanium, Silicon Wood, Rubber, Mica, Paper

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Kishu Raj 7 years ago

According to their conductive property. Conductor conduct electricity, insulator do not conduct electricity while semiconductor have the intermediate property of conductor and insulator.

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What is transister and reactifer ?

Posted by Gagandeep Rathi 7 years ago

CBSE > Class 12 > Physics