CBSE > Class 12 > Physics | CBSE Board | Homework Help

Ofcourse convex lens is a converging lens but in a special case when *(the refractive index of the surrounding medium is greater than the refractive index of lens material) then is acts as diverging lens. Likewise in concave lens for the same condition*() mentioned above it acts as converging lens.

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Sanskriti S 6 years, 9 months ago

hey, u 're wrong.... convex lens is converging, not diverging!!

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Nivetha Vijayakumar 6 years, 9 months ago

The reason is that, the refractive index of the medium is greater than the refractive index of the lens. Hence, it acts as diverging lens.

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How to get 70 marks in physics class 12th

Posted by Ravinder Singh 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

Sanskriti S 6 years, 9 months ago

smart work, along with hard work... pdh k to sab aate h!!

1Thank You

ANSWER

Is transistor as a switch and transistor as an oscillator is included in cbse syllabus

Posted by Deep Bal 6 years, 9 months ago

CBSE > Class 12 > Physics

5 answers

Nitika Neb 6 years, 9 months ago

Transistor as a switch is not in syllabus of cbse we have to do oscillator

2Thank You

Deep Bal 6 years, 9 months ago

Plz tell which topics we have to do in transistor

0Thank You

Deep Bal 6 years, 9 months ago

But in this app they had only given transistor as an amplifier in cbse syllabus

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Akash Porwal 6 years, 9 months ago

No its out of syllabus .if u need knwledge than u can go through it

1Thank You

Utsav Aryan 6 years, 9 months ago

Yes

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ANSWER

A charged rod P attracts rod R, whereas P repels another charged rod Q. What type of force developed between R and Q?

Posted by Nivetha Vijayakumar 6 years, 9 months ago

CBSE > Class 12 > Physics

3 answers

Nivetha Vijayakumar 6 years, 9 months ago

No thanks. I understood. Thanks for your guidence.

0Thank You

Nivetha Vijayakumar 6 years, 9 months ago

Thank u but may i know the reason pls.

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Aayushi Srivastava 6 years, 9 months ago

attractive force

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Can anyone explain me davison germer experiment

Posted by Mohit Singh 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

Akash Porwal 6 years, 9 months ago

Then using braggs law u can find lamfa

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Akash Porwal 6 years, 9 months ago

In this electron gun ejects electrons and strike on nickel crystall and a rotating detector is placed and we determine the deviated angle

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ANSWER

Derive an expression for the electric field at a point on the axial position of an electric dipole.

Posted by Yash Bhavsar 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

Diksha Kharwal 6 years, 9 months ago

https://www.topperlearning.com/doubts-solutions/derive-an-expression-for-electric-intensity-due-to-electric-dipole-along-axial-line-and-equitorial-line-u0k14p22

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ANSWER

Define curie's law

Posted by Jahangir Siddiqui 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

Nivetha Vijayakumar 6 years, 9 months ago

Bro i don't think this topic is important coz it is used only to differentiate b/w para-, dia-, & ferro- magnetic substances. Also that will be asked only for 4 marks(max.) for which max. of 3 points are enough with an example of each.

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Nivetha Vijayakumar 6 years, 9 months ago

It states that the magnetisation of a paramagnetic substance is inversely proportional to the absolute temperature. I = C (B0/T).

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B on axis of circular loop by using biot savrat law

Posted by Nidhi Chauhan 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Give me tips for covering whole syllabus before 2 days exam

Posted by Mehwish Kehkeshan 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

G K 6 years, 9 months ago

Do sample paprs?

2Thank You

Vitthal Gupta 6 years, 9 months ago

learn derivation and some important point definitions take over view of all chapter from ncert and by guide learn the formula also

2Thank You

ANSWER

Explain the working of isosceles prism and Optical Fibre

Posted by Neha Pachani 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

Nivetha Vijayakumar 6 years, 9 months ago

Optical Fibres: This also uses TIR. Here the refractive index of the core must be higher than that of cladding. So, when the signal in the form of light is directed from one end at a suitable angle, it undergoes repeated TIR and comes out from the other end. Therefore, no absorption of light takes place. (Core refers to the inner space of the tube, cladding refers to the material of the outer coating) Uses: Transmitting electrical & optical signals, decorative lamps, etc.

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Nivetha Vijayakumar 6 years, 9 months ago

Right angled isoceles prism: These prism turn the light by 90°or 180°. They are based on the phenomenon of total internal reflection of light. The refractive index for glass is 1.5, therefore the critical angle for glass - air interface is 42° (as refractive index = 1/sin ic). When the angle of incidence is > 42°, for example, 45° the total internal reflection takes place. Uses: to invert the image without changing the size(TIR).

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Gave me tips for covering my whole syllabus before two days of exam

Posted by Akash Joshi 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

G K 6 years, 9 months ago

Sample papr kro dost ...

0Thank You

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Why is more energy obtained from nuclear fusion than nuclear fission?

Posted by Kunal Sharma Bhardwaj 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

A magnet is quickly moved in the direction indicated by an arrow between coil c1 and c2 as shown in figure.what will be the direction of induced current in the coils...

Posted by Anukriti Gupta 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Is van de graff generator in syllabus???

Posted by Anjali Sharma 6 years, 9 months ago

CBSE > Class 12 > Physics

3 answers

Akash Joshi 6 years, 9 months ago

1Thank You

Sakshi Singh 6 years, 9 months ago

Nope

1Thank You

Vibhor Shandilya 6 years, 9 months ago

1Thank You

ANSWER

Why do electric field lines does not cross each other?

Posted by Meghaa Govidaraju 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

Abhinav Tiwari 6 years, 9 months ago

If electric feild lines intersect each other then electric field has two tangential direction which is not possible so they never interesect each other

1Thank You

Vibhor Shandilya 6 years, 9 months ago

Cause at point of intersection their are 2 different direction of electric field which is not possibel

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Write the principle of transformer

Posted by Kartik Sharma 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Rheostat of 100 turns of wire of radius 0.4m having R=4.2×10^-7 the diameters of each turn is 3cm what is the max resistance it can provide? How to solve

Posted by Amal Roshan 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Function of a transmitter in a communication system?

Posted by Osotot Sharma 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Mention the function of band pass filter

Posted by Ak Chaudhary 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

Aayushi Srivastava 6 years, 9 months ago

band pass filter the frequency of high and low ramge...and pass only bands of frequency....

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ANSWER

Why a photo diode is used in reverse biasing

Posted by Ak Chaudhary 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is the most common use of photo diode

Posted by Ak Chaudhary 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

Aayushi Srivastava 6 years, 9 months ago

used in electronic devices ...can be used as fastest photodetector as it can turns it current on and off

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ANSWER

The thermal speed of free electrons are very large. Inspite of these high speed why they fail to escape from the surface of a conductor

Posted by Khushal Vaid 6 years, 9 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

I have only 1 day left for my exam.i have not read anything.What topics should i read to pass??

Posted by Moti Satapathy 6 years, 9 months ago

CBSE > Class 12 > Physics

2 answers

Riya Singhal 6 years, 9 months ago

Gauss theorem&lenz law also imp.

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Nitika Neb 6 years, 9 months ago

Cyclotron,solonoid ,compound microscope,astronomical telescope,ac generator,youngs double slit experinment

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ANSWER

Sir I not understand radioactive law

Posted by Abhishek Dwivedi 6 years, 9 months ago

CBSE > Class 12 > Physics

1 answers

Nitika Neb 6 years, 9 months ago

The radioactive decay law states that the probability per unit time that a nucleus will decay is a constant, independent of time. The radioactive decay of certain number of atoms (mass) is exponential in time. Radioactive decay law: N = N.e-λt. The rate of nuclear decay is also measured in terms of half-lives

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Name the process by which exact reproduction of a document at a distant place can be received.

Posted by Sarwesh Tiwari 6 years, 9 months ago

CBSE > Class 12 > Physics