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What is the change in capacitance and charge when dielectric slab of width equal to the separation of plates in parallel plates capacitor and battery is always connected to capacitor?

Posted by Rahul Kumar Choudhary 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Kashmiri Devi 6 years, 10 months ago

The capacitance of the capacitor increases

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What is nucleosides

Posted by Hitler Tiger 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

A nucleoside consists of a nitrogenous base covalently attached to a sugar (ribose or deoxyribose) but without the phosphate group. Several nucleoside analogues are used as antiviral or anticancer agents. Examples of nucleosides include cytidine, uridine, adenosine, guanosine, thymidine and inosine.

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I haven't read physics whole year . Can u plzz help me how to get atleast good marks . I know i have no time but plzz help me so that i can pass . Please

Posted by Shesh Nath Kumar 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

Shesh Nath Kumar 6 years, 10 months ago

Thanx bhai

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Bipul Shreyas 6 years, 10 months ago

Its same with me but what I am doing is just solving previous year questions and ncert examples and exercises

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Which material is used for the metre bridge wire and why

Posted by Abhishek Kashyap 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

The material of wire used in meter bridge is made of manganin or eureka due to there high specific resistance or resistivity. Thick copper strips are used in meter bridge because copper is a good conductor of electricity.

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Why it is generally preferred to obtain the balance point in the middle of the metre bridge wire

Posted by Abhishek Kashyap 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

The balance point is obtained in the middle of the bridge wire for the following reasons.
1. When the balance point is in the middle of the bridge wire, the resistance in the four arms P, Q, and X become of the same order and consequently the bridge becomes most sensitive.
2. If some error occurs in locating the balance point, the error in the measured value of the resistance will be comparatively smaller.
3. The error due to end resistance is reduced.

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Why are the connection between the resistor in a metre bridge made of thick copper strip

Posted by Abhishek Kashyap 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

The connections are made of thick copper wires to minimize the resistance of connecting wires. Because the connection resistance have not been accounted in the formula, (v Resistance is inversely proportional to cross-sectional area, so thick wire has low resistance).

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Show variation of resistivity of copper as a function of temperature in a graph

Posted by Abhishek Kashyap 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

The graph below shows variation of resistivity of copper with temperature. The graph is parabolic in nature.

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How is sunlight is polarised through linearly polarised light. Explain?

Posted by Khushboo Kumari 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

Linearly polarised light is the light wave in which the vibration of electric field vectors are confined in one plane and parallel to one unique direction. The intensity of transmitted light becomes maximum, when the inserted polaroid and analyser (the polaroid which receives light that is transmitted by inserted polaroid) have their axes parallel to each other.
The incident sunlight is unpolarized. Molecule in air acts as a dipole radiator. When the sunlight falls on a molecule, dipole molecule does not scatter energy along the dipole axis; however the electric field vector of light wave vibrates just in one direction perpendicular to the direction of the propagation. The light wave having direction of electric field vector in a plane is said to be linearly polarized.

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What is linearly polarized light .Please explain this question with easy language.

Posted by Khushboo Kumari 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 6 years, 10 months ago

When an unpolarized light is transmitted through a polarizer, only one component is along the direction of propagation. This transmitted light is called as linearly polarized light.

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Explain the significance of direction of electric current in a circuit.

Posted by Leena Gupta 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Adil Khan 6 years, 10 months ago

Positive to negative

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Two magnetic poles one of which is four times stronger than the other exert a force of 10 gf on each when placed at a distance of 10cm in air. Find the strength of each pole

Posted by Leena Gupta 6 years, 10 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Why lighter elements are better moderators than heavier elements

Posted by Leena Gupta 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Siddhant Gaurav 6 years, 10 months ago

Lighter elements has high binding energy per nucleons due to which the high speed neutrons collide with moderator speed become less and convert to thermal neutron which is able to break uranium

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Express biot savart law in the vector form

Posted by Laxminarayan Yadav 6 years, 10 months ago

CBSE > Class 12 > Physics

3 answers

Pragya Gupta 6 years, 10 months ago

Mo / 4π idl sin 90. = dB

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Rakesh Thakran 6 years, 10 months ago

dB = KI (dl × r)/ r3

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Nehal Mehta 6 years, 10 months ago

•First multiply 'r' on num and deno in the obtained expression of biot savart law •You'll get the final expression in vector form as: UoI/4π × dl×r/r^3

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What is the percentage error in measuring path difference in Young's experiment

Posted by Shubham Sharma 6 years, 10 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

State brewesters law

Posted by Manish Kadam 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

Yogita Ingle 6 years, 10 months ago

Brewster’s Law: It states that when light is incident at polarising angle at the interface of a refracting medium, the refractive index of the medium is equal to the tangent of the polarising angle.
As Brewster angle depends on the refractive index and wavelength, so it is different for different colours

1Thank You

Siddhant Gaurav 6 years, 10 months ago

refractive index of denser medium is equal to Tanip where ip is angle of polarisation and angle of polarisation is that angle of incident at which reflected light is fully polarised

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A ray of monochromatic light passes from 1 medium to 2 medium if the angle of i in 1 medium is ∆ and the angle of r in medium 2 is ∆/ 2 which medium is optically denser and why ?

Posted by Parthvi Kataria 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Siddhant Gaurav 6 years, 10 months ago

I think medium 1 is optically denser bcoz yaha pe total internal reflection ho rha h and ye process hone k liye incident ray must be in denser medium

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State brewsters law

Posted by Manish Kadam 6 years, 10 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Aap me se asa kon h jiska physics ka pura syllabus ho gya ho........

Posted by G K 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

G K 6 years, 10 months ago

I m just asking for survey.....not more than tht

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Rakesh Thakran 6 years, 10 months ago

Bhai yeh toh 4march tak bhi nahi hoga

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If the electricity produced b/w two neutral bodies is frictional electricity then how do "A" and "B" gets positive n negative charge on them while rubbing?

Posted by Shruti Singh 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Siddhant Gaurav 6 years, 10 months ago

There is transfer of charge occurs as we all know everything has charge if a body A loses charge then it gets positive charge and body B gain charges so it has negative charges

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What is RADAR communication

Posted by Sakshi Yadav 6 years, 10 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is refrective index

Posted by Rahul Singh 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

Gagan Preet Kaur 6 years, 10 months ago

The ratio of speed of radiation in one medium to that in another medium

1Thank You

Mehak Gupta 6 years, 10 months ago

It is a measure of angle by which a light ray will bend when it travels from one medium to another

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State the criteria for the phenomena of total internal reflection of light to take place ?

Posted by Sneha Kaushik 6 years, 10 months ago

CBSE > Class 12 > Physics

4 answers

Pragya Gupta 6 years, 10 months ago

The light mist be travel frm optically denser to rarer medum

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Siddhant Gaurav 6 years, 10 months ago

Angle of incidence must be in denser medium

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Sayeda Iram Ateeq 6 years, 10 months ago

?? & the refrection is takes place from densor to rarer medium!!

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Mehak Gupta 6 years, 10 months ago

Angle of incidence should be greater than critical angle

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Why does the sun look reddish at sunset or sunrise?

Posted by Sneha Kaushik 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

Yogita Ingle 6 years, 10 months ago

Sun is at the farthest distance during sunset and sunrise.the white light from the sun gets scattered as it travels towrds the earth. The blue colour gets scattered the most, the lightreaching teh eye has white light minus blue light scattered away. red light which is relativley less scattered reaches us the max. hence the sun appears red.

1Thank You

Kartik Periwal 6 years, 10 months ago

Beacuse the sun rays travels long distance and therefore the colour with shorter wavelengths are removed by scattering and the colour with longest wavelength reaches our eye i.e. red

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In a uniform electric field E, the potential difference between two points A and B is 1volt. Ut is given that AB=4cm and angle =60 with E. Find the field strength E

Posted by Anubhav Tripathy 6 years, 10 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Difference between LED and Solar cell?

Posted by Jeevan John 6 years, 10 months ago

CBSE > Class 12 > Physics

3 answers

Krishna Ahari 6 years, 10 months ago

LED works in forward bias and solar cell has no bias

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Rishabh Jain 6 years, 10 months ago

Solar cell concerts light energy into electrical energy while LED is vice versa

1Thank You

Lovepreet Khalsa 6 years, 10 months ago

I dont know

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Two point charges having equal charges separated by 1m experience a force of 8N what will be the force experienced by them if the are placed in water having same distance

Posted by Abhishek Kumar 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Shubham Sharma 6 years, 10 months ago

0.1N

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Velocity selector

Posted by Bhanu Pratap Meena 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Hiwani Agrawal 6 years, 10 months ago

V =E/B

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ANSWER

the electric current flowing in a wire in the direction from B toA is decreasing. find out direction of induced current in the metallic loop kept above it.

Posted by Teresa Ma 6 years, 10 months ago

CBSE > Class 12 > Physics

1 answers

Krishna Ahari 6 years, 10 months ago

Direction of induced current if clockwise

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Expression of drift velocity of free electrons

Posted by Nitika Neb 6 years, 10 months ago

CBSE > Class 12 > Physics

2 answers

Sayeda Iram Ateeq 6 years, 10 months ago

EXPRESSION FOR DRIFT VELOCITY: Avg. thermal velocity of electrons in a wire is zero. When an electric field is applied, force on an electron, F=eE Acceleration produced, a= F/m a= eE/m If Ț be the relaxation time, then the drift velocity, Vd= Thermal vel. + aȚ Vd= 0 + eE Ț/m Hence, "Vd= eE Ț/m"

1Thank You

Shubham Sharma 6 years, 10 months ago

V = eE ×RELAXATION TIME ( t )÷m

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A convex lens is used to obtain a magnified image of a object on a screen 10 cm from the lens . If the magnification is 19 find focal length of the lens ??????????????????????

Posted by Mahera Ansari 6 years, 10 months ago

CBSE > Class 12 > Physics