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Sample paper is just an idea to know what is the pattern of upcoming question paper and who the marks are divided.. It doesnt means that question given sample paper will come in exam. If they come its ur luck

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si unit of sigma

Posted by Guddu Masih 6 years ago

CBSE > Class 12 > Physics

3 answers

Riya Rana 6 years ago

C/m^2

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Geetanjali Rathod 6 years ago

Compare to second sigma is smaller unit

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Geetanjali Rathod 6 years ago

1 sigma =10 *-6 second

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two identical charged particles moving with same speed enter a region of uniform magnetic field if one of these enter normal to the field direction and other enters along a direction at 30 degree with the field what would be the ratio of their angular frequencies?....choose--a)1:2 or b)1:1??

Posted by Muskaan Vig 6 years ago

CBSE > Class 12 > Physics

5 answers

Gaurav Kumar 6 years ago

1:1

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Tamanna Sharma 6 years ago

When perpendicular to the field qvB = mv^2/ r,hence angular frequency is v/ r= qB/m,,,,and at angle 30° qvsin30°B= mvsin30° ^2/r hence angular frequency is vsin30°/r = qB/ m .in both cases a.f is same so ratio is 1:1

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A ? 6 years ago

1 : 2

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Muskaan Vig 6 years ago

please tell me why?

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Riya Rana 6 years ago

1:1

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The resultant of two forces 10N and 15N along +xaxis and -xaxis is respectively???

Posted by Javali Jonu 6 years ago

CBSE > Class 12 > Physics

1 answers

Tamanna Sharma 6 years ago

-5N it's colinear vector ( anti parallel in this case)

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A wire has resistance of 12 ohm it is bent in the form of circle the effective resistance between the two point on the diameter of the circle is

Posted by Ajay Sharma 6 years ago

CBSE > Class 12 > Physics

2 answers

Shatayu Ganvir 6 years ago

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Ajay Sharma 6 years ago

The two semicircular part each of 6 ohm are in parallel 6×6/6+6 = 36/12 = 3 ohm

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Relation between electric field and current density

Posted by Ajay Sharma 6 years ago

CBSE > Class 12 > Physics

2 answers

Yogita Ingle 6 years ago

Current density J is a vector quantity which is defined as the current flowing per unit area measured in a direction normal to the direction of flow of charge.

|J| = |I|/ A

Substituting the value of I and Vd in this equation |J| = |I|/ A ;

|J|= nAqVd / A

= nq. (qt|E|/ m)

|J| = (nq²t/ m).|E|

The vector J is parallel to the electric field vector.

In the above equation the quantity nq²t/ m is called conductivity σ.

|J| = (nq²t/ m).|E| = σ |E|

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Tamanna Sharma 6 years ago

J= sigma E

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I have maximum of the questions but still i am not confident about it

Posted by Koshal Kumar 6 years ago

CBSE > Class 12 > Physics

3 answers

Becky Shoshannah 5 years, 11 months ago

U'll do great! Just believe in yourself and God

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Koshal Kumar 6 years ago

To kya karu

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Riya Rana 6 years ago

Happens with everyone

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Bye friends....again all the very best

Posted by Nikita Beniwal 6 years ago

CBSE > Class 12 > Physics

1 answers

A ? 6 years ago

Byeee...????✌✌?

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A rectangular wire frame is placed in a uniform magnetic field directed upwards and normal to the plane of paper. The part AB is connected to a spring . the spring is stretched and released when the wire AB has come to the position A'B' (t=0). How would the induced emf vary with time? Neglect damping

Posted by Sonakshi Raj 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is electric flux ?and its SI unit with dimension

Posted by Rohit Saklani 6 years ago

CBSE > Class 12 > Physics

4 answers

Apoorva Rao 6 years ago

NCm-2

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Apoorva Rao 6 years ago

Electric Flux is the no.of electric field lines passing through a surface area normally

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Prafull Jha 6 years ago

No of electric field lines passing perpendicular to the surface is called electric flux. SI unit- (N/C)m^2 Dimension-ML^3T^-3A^-1

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Nikita Beniwal 6 years ago

No. Of electric field lines passing through particular area

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All the best for board 2020...

Posted by Nikita Beniwal 6 years ago

CBSE > Class 12 > Physics

4 answers

Nikita Beniwal 6 years ago

Welcome

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Kriti Sharma 6 years ago

Thanks niki......??????

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Manvendra Singh 6 years ago

Same to you

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A ? 6 years ago

Same to u...?

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Principal of half wave rectifier?

Posted by Ankur Dahiya 6 years ago

CBSE > Class 12 > Physics

2 answers

Prafull Jha 6 years ago

it is based on the fact that diode conduct electricity or allow to pass current through it. it conduct electricity in FB and does not conduct in RB.

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Manvendra Singh 6 years ago

Spelling of principle is wrong

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Main topics to learn ?

Posted by Shivam Yadav 6 years ago

CBSE > Class 12 > Physics

1 answers

Nilesh Hiragar 6 years ago

Bro all the topic r main

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Prove that in a radial magnetic field the deflection of coil is directly proportional to the current flowing in the coil

Posted by Kirthi Prabhudessai 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Name the EM waves used for studying crystal structure of solids

Posted by Josna Mary Thomas Thomas 6 years ago

CBSE > Class 12 > Physics

2 answers

Muskaan Vig 5 years, 11 months ago

X-Rays are used for studying crystal structure of solids..

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Ritwik Choudhary 6 years ago

Gamma rays

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Name the elements which shows +3 oxidation state?

Posted by Prakash Kumar 6 years ago

CBSE > Class 12 > Physics

2 answers

Shefu ??????? 6 years ago

Scandium and group 15 elements

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Riya Rana 6 years ago

Scandium

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Sir 2021 ka syllabus kab aayega

Posted by Dilnawaz Farooqui 6 years ago

CBSE > Class 12 > Physics

2 answers

Tushar Bhola 5 years, 11 months ago

Bhai fail hokar fir se 12 karni hai kya

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Tamanna Sharma 6 years ago

3000 tak aa jayga

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While deriving potential due to dipole how do we find r1 and r2?

Posted by Sunita Devi 6 years ago

CBSE > Class 12 > Physics

2 answers

Riya Rana 6 years ago

Okk

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Sunita Devi 6 years ago

I got it

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What is one side deflection?when it occur and how can we rectify it?

Posted by Prafull Jha 6 years ago

CBSE > Class 12 > Physics

1 answers

Tamanna Sharma 6 years ago

1. When the source cell emf is less than to the comparable cell.,,,,2.when connection is not right.(+ve of potentiometer is connected to the-ve of the cell which we have to compare. ...rectify it by making right connections and suitable emf cell choosen.

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Principal of cyclotron

Posted by Abdul Raziq 6 years ago

CBSE > Class 12 > Physics

4 answers

Arpita Mengi 6 years ago

It works on the the principle that when a charged particle moving normal to mag. Field it feels the magnetic force due to which it starts moving in circular path

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Sg Tech 6 years ago

Time taken for one revolution is independent of its speed and radius

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Sanskriti Sinha 6 years ago

Cyclotron works on the principal of mutually perpendicular electric and magnetic field.

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Prafull Jha 6 years ago

A charge particle can acquire very high K.E by crossing the same electric field again and again with the help of uniform perlendicular magnetic field

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Youngs double slit experiment derivation

Posted by Parth Deshmukh 6 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Does our syllabus contain limit of resolution??

Posted by Aryan Bhavsar 6 years ago

CBSE > Class 12 > Physics

1 answers

Bhanu Arora 6 years ago

Yes, its a part of wave optics' resolving power of telescope and microscope

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Important question of chapter wave optics

Posted by Suchi Mishra 6 years ago

CBSE > Class 12 > Physics

4 answers

Mitali Jain 6 years ago

Polarisation and Young's experiment

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A ? 6 years ago

Ydse

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Pooja Rawat 6 years ago

Polarisation topic

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Tevar Jaat 6 years ago

Double slit experiment

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What is reason behind reverse breakdown ?

Posted by Naina20 Tiwari 6 years ago

CBSE > Class 12 > Physics

3 answers

Naina20 Tiwari 5 years, 11 months ago

Thank you

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Rajat Barwar 6 years ago

Drastic breaking of large no. of covalent bonds.

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Manjay Jha 6 years ago

Current is quite small and is independent of voltage.

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Derive the electric field intensity at axial line

Posted by Ramsha Faiz 6 years ago

CBSE > Class 12 > Physics

2 answers

Apoorva Rao 6 years ago

Considering an electric dipole ab =2a and a point p is in the axial position with dipole movement p=q.2a Electric field intensity at point p due to +q=1/4pie€0. q1q2/r²- a² Electric field intensity at point of due to _q=1/4pie€0.q1q2/r²+a² Net electric field intensity =E1+E2=2rp/(r²-a²)²

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Sunita Devi 6 years ago

You can watch video from lesson to know that

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What we have to study about De Broglies explanation of Bohrs 2nd postulate

Posted by Josna Mary Thomas Thomas 6 years ago

CBSE > Class 12 > Physics