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

The focal length ( f ) is the distance from a lens or mirror to the focal point ( F ). (right) a concave mirror. ... Note that a lens has a focal point on both sides of the lens axis. Light rays that are parallel to each other, but not to the optical axis, will meet on the focal plane.

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Yogita Ingle 5 years ago

A convex lens is a lens with an outward curve. Unlike the concave lens, the thickness at the centre of a convex lens is more than the thickness at the edges of the lens. Convex lenses are converging lenses. They have the ability to converge a parallel beam of light into a point. This point is called the focal point of the convex lens and the distance from the optical centre to the focal point is called the focal length. The focal point is on the opposite side of the lens from which the light rays originate.

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Is deflection of a beam in an electric or magnetic field a convincing proof of its particle nature

Posted by Aradhana Singh 5 years ago

CBSE > Class 12 > Physics

1 answers

Tanisha Yadav 5 years ago

The force applied on an electron due to electric field is given by F =q E . But the charge on electron is negative. Hence according Newton's second law of motion, electron deflects accelerates opposite to the direction of electric field.

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Write the dimension formula for capacitance

Posted by Keshav Joshi 5 years ago

CBSE > Class 12 > Physics

4 answers

Iqbal Singh 5 years ago

M^-1L^-2T^4A^2

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Tanisha Yadav 5 years ago

Since charge on a capacitor with capacitance C is given by q=CV, therefore, C= V q . Hence, [C]= V q = [ML 2 T −3 A −1 ] [AT] =[M −1 L −2 A 2 T 4 ]

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Krati Varshney 5 years ago

M-1.L-2.A2.T4

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Keshav Joshi 5 years ago

I don't know

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Define dielectric constant of a medium in terms of force b/w electric charges?(in simple words?)

Posted by Ayushi Kurmi 5 years ago

CBSE > Class 12 > Physics

1 answers

Tanisha Yadav 5 years ago

The dielectric constant of a medium is the ration of force between two charges placed some distance apart in vacumm to the force between same two charges placed same distance apart in the given medium

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The efficiency of machine is 60% if input energy is 50J so output energy is

Posted by Raja Yadav 5 years ago

CBSE > Class 12 > Physics

3 answers

Raja Yadav 5 years ago

I want solution this question

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Khushi Jaiswal 5 years ago

I think this is correct answer ??

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Khushi Jaiswal 5 years ago

For an electrical powerconversion process, efficiencyis measured simply by dividing the output power in watts by the input power in watts and is expressed as a percentage.

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A object is placed in front of concave lens of focal length 10 cm.If the concave lens from a vertical image magnification 0.5. Find the position of object and position of image?

Posted by Moin Ali 5 years ago

CBSE > Class 12 > Physics

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A proton is ejected with a speed of 8×10⁶ ms-¹ in an uniform magnetic field of strength of 0.1 T at angle of 30° with the direction of magnetic field. Calculate 1. The radius and the time period of the helicle path 2. Calculate the pitch of the helix? Given mass of the proton= 1.67×10-²⁷ kg.... Please help me?

Posted by Tralokya Nath 5 years ago

CBSE > Class 12 > Physics

2 answers

Durga Kumari 5 years ago

Hii. Tralokya Nath .......i can suggest you to Google the question as it is........just open the mic and recite the question line to line and you will get many sites that offer you with free solutions. Regards?

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Khushi Jaiswal 5 years ago

The radius and the time period of the helicle path 2. Calculate the pitch of the helix? Given mass of the proton= 1.67×10-²⁷ kg.

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Hi have one doubt

Posted by Varun Sharma 5 years ago

CBSE > Class 12 > Physics

3 answers

Tanya ?? 5 years ago

What is your doubt varun...?

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Akanksha Kumari 5 years ago

¿¿¿¿¿¿¿¿¿

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Iqbal Singh 5 years ago

what doubt dear ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

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Magnetic field induction at the centre of Pentagon if its side a carries a current I ampere.

Posted by Shubham Gupta 5 years ago

CBSE > Class 12 > Physics

1 answers

Khushi Jaiswal 5 years ago

the triangle AMO, the angle can be written as, tanθ=r2l tan30∘=r2l r=23l The magnetic field due to the side AB is given as, BAB=4πμ0×ri(sinθ+sinθ) =4πμ0×r2isinθ =4πμ0×23l2isin30∘ =4πμ0×3l2i Total magnetic field at the centre is given as, Bo=6BAB =6×4πμ0×3l2i =πlμ0i3

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A spring of a force constant 24 N/m is resting on a frictionless horizontal surface.A force of 10N is applied on the block of mass 4kg at one end of the spring .what is the speed of block when it has been moved through a distance of 0.5m ?

Posted by Monikasrinivas. Monikasrinivas. 5 years ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is 1 farad?

Posted by Aditya Sharma 5 years ago

CBSE > Class 12 > Physics

1 answers

Yogita Ingle 5 years ago

One Farad is defined as the capacitance for a particle with one Coulomb charge and with the potential difference of one Volt.

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Feredy experiment

Posted by Jogi Sharma 5 years ago

CBSE > Class 12 > Physics

0 answers

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Euipotential surface Who is father of physics What is magnetisation What is intrinsic semiconductor पीएन junction diode rectifier half wafe Led zenor deoide

Posted by Rishu Singh 5 years ago

CBSE > Class 12 > Physics

1 answers

Tanisha Yadav 5 years ago

Father of physics=Issac Newton Father of modern physics=Albert Einstein

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The electrostatic force between two protons situated at a distance x from each other is y newton what will be the electrostatic force between two electrons situated at the same distance

Posted by Aradhana Singh 5 years ago

CBSE > Class 12 > Physics

1 answers

Vikas Shukla 5 years ago

The magnitude of force will be same. I think so because the charge on proton and electron is same it's just positive and negative respectively but in both cases charges are same so the force exerted in both cases must be same i.e. y newton and repulsive in nature so +ve sign.

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Two parallel capacitor

Posted by Erza Scarlet 5 years ago

CBSE > Class 12 > Physics

1 answers

Tanisha Yadav 5 years ago

When capacitors are connected in parallel, the total capacitance is the sum of the individual capacitors' capacitances. If two or more capacitors are connected in parallel, the overall effect is that of a single equivalent capacitor having the sum total of the plate areas of the individual capacitors.

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four charges 50 micro coulomb,-50microcoulomb and 50 microcoulomb are places at the corners A,C,And D of a square

Posted by Sneha Das 5 years ago

CBSE > Class 12 > Physics

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A voltmeter is connected in parallel with a variable resistance R which is in series with an ammeter and a cell the meter reads 0.3A and 0.9V .for another value of R the reading are 0.25A and 1.0V .what is the value of internal resistance of the cell

Posted by Shweta Patidar 5 years ago

CBSE > Class 12 > Physics

0 answers

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Hello guys ,how r u all.kon kon neet aspirants ho.....

Posted by Piyush Parjapati 5 years ago

CBSE > Class 12 > Physics

3 answers

Akanksha Kumari 5 years ago

Actually i'm confused what to do after 12th

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Mahendra Rathor 5 years ago

hii I m also neet aspirant

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Iqbal Singh 5 years ago

hello

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What is meant by a circuit how will you compare it to electrical circuit ? Define the term reluctance , magneto-motive force

Posted by Astitva Satsangi 5 years ago

CBSE > Class 12 > Physics

1 answers

Akanksha Kumari 5 years ago

An electric circuit can be defined as a closed path through which electric current can flow. ... reductance ,the property of a magnetic circuit of opposing the passage of magnetic flux lines, equal to the ratio of the magnetomotive force to the magnetic flux. ..... In physics, the magnetomotive force is a quantity appearing in the equation for the magnetic flux in a magnetic circuit, often called Ohm's law for magnetic circuits. ...

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How should i prepare notes for revision for 12 board exams

Posted by Ekanshi Jawla?????? 5 years ago

CBSE > Class 12 > Physics

5 answers

Iqbal Singh 5 years ago

hi aksah

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Akash Dubey 5 years ago

Hii all of you

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Mishti ???? 5 years ago

Dear make it from NCERT textbook by writing topic wise for example take a topic write it's small defination as u can & then write the formula n derivation of it & If any special case .... Cover each n every topic of NCERT as ??& then write numericals which was topic by topic for better understanding.... I hope it will help u Regards....??

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Iqbal Singh 5 years ago

yes in this app good notes r avaliable ?? ALL THE BEST FOR EXAMS G

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Akanksha Kumari 5 years ago

In this app notes is also available u can check ☺️

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Is parallel and series combination are in syllabus?

Posted by Akanksha Kumari 5 years ago

CBSE > Class 12 > Physics

5 answers

Akanksha Kumari 5 years ago

???? thanks g

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Usha Yadav 5 years ago

Hiii Parallel and Series combination of resistance is not in Syllabus of 2020 But Parallel and Series Combination of Capacitor is in Syllabus of Physics for 2020. I hope it would help you.........

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Iqbal Singh 5 years ago

no g

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Akanksha Kumari 5 years ago

Thanks dude

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Romi Shukla 5 years ago

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Can anyone suggest me any website for objective questions of pcm????????

Posted by Akanksha Kumari 5 years ago

CBSE > Class 12 > Physics

3 answers

Akanksha Kumari 5 years ago

Thanks dude

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Mishti ???? 5 years ago

U can use learncbse.. or Jagran josh... Dear Or byju's too ... Regards.??

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Iqbal Singh 5 years ago

I suggest u studyadda

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How to learn all the derivation of physics...it's quite hard!!

Posted by Arpita Sharma 5 years ago

CBSE > Class 12 > Physics

5 answers

Usha Yadav 5 years ago

Hii From my Views it seems that Your Understanding and accuracy Should be better.... Because In physic everything is surrounded about us Like , Electricity, Magnet, AC( Alternative current) , Waves ,Light , Communication, Metal ,non metal , Semi conductor, Problem is to Observe all of them Use of it .. Concept behind all These.... If you have a little bit Knowledge then you will be able to derive the formula ...of that topic with out any Teacher HELP........ So ,Virtualize all these concept and Information about all these...

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Mishti ???? 5 years ago

Ya dear u have to understand that why we using this step or formula to do next... Because rattafication can't help u in derivation because if u forget any of the step it will be wrong dear...

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Iqbal Singh 5 years ago

there r many tricks to learn it

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Vikas Shukla 5 years ago

Don't learn them! They might seem more tough if you learn them. Try to understand each step. Try to know why are u writing that particular formula. This will be a bit hard in starting but gradually u will become used to it. Try to understand the concept behind derivation rather learning them.

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Pradeep Yadav 5 years ago

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Can anyone tell me..how can I revise my physics syllabus mujhe samaj nhi aa rha m kaise start kru aur meri physics ki bilkul bhi revision nhi h Can anyone help me

Posted by Tanya ?? 5 years ago

CBSE > Class 12 > Physics

5 answers

Mishti ???? 5 years ago

I may suggest that do derivation after every topic & not only one type use more conceptual that u find easily in SL arora or pradeep ,so after doing the topic u must ...try numerical of that type ... Firstly try to do by yourself dear ... 1 write what is given in question 2 apply the formula by putting values, in beginning the numericals are easy it's like that u put the vale & got answer but then it is like that u have to change the units to this to that.... It make confidence in u that u can do it... & Then try to solve the exercise....hope it will help u dear Regards...??

1Thank You

Vikas Shukla 5 years ago

I too face this problem while solving numericals. You must practice and practice the numericals. The only reason behind inability to solve numericals is that you don't know formula because u don't have enough practice. If u find derivations easy then u must pay more attention to numericals. Start from easy and then head toward the tough portion.

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Tanya ?? 5 years ago

Yes u both r right...pr problem ye h ki m sari derivations ko bilkul aache se revise kr leti hu ...pr jb numericals aate h na to mujhe kuch smj nhi aata ki konsa formula lagega mujhse numericals solve nhi hote m bahut try krti hu.... 11th m bhi mere physics m sirf derivations k no. Aae the aur 1 ya 2 numericals k....To m ye puchna chahati hu ki m numericals kaise solve kru

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Mishti ???? 5 years ago

Use previous year question chapter wise & tick the concept which is mostly asked & strong those topics. Study NCERT & solve it's example n exercise.. Regards.

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Gungun Arya Gupta 5 years ago

You have enough tme still . First study ncert book and then revise your notes . And solve quetions of that topic which is you read

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A capacitor or 4 μF is connected in circuit . The internal resistance of battery is 0.5 ohm. The Amount of charge on the capacitor plates will be ?

Posted by Namrata Sahu 5 years ago

CBSE > Class 12 > Physics