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

For yellow 4 green 5 and orange 3for orange it is raised to power of 10 thus resistance is 45×10pawer of 3 +_ 5% for gold 10%for silver and 20%for no colour Thus voltage drop is V=IR v=45×10×3 +_5% ×2

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Diagram for non conducting and conducting spherical shell Plzzzzzzzzzzzzzz,

Posted by Neelam Kari Kumari 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Neelam Kari Kumari 6 years, 3 months ago

Did you know the diagram i am just have little confusion may i asked?

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Aman Kumar 6 years, 4 months ago

Sorry, mate but diagram can't be possible here...

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What is electric dipole

Posted by Aashok Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Vinay Ranjan 6 years, 4 months ago

A pair of equal and opposite charges seperated by a small distance...

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Prerna Dashondhi 6 years, 4 months ago

The pair of two equal an opposite charges separated by small distance 2a called electric dipole

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Abhijeet Rajput 6 years, 4 months ago

A system in which two opposite charge but same magnitude are separated by very short distance is called electric dipole.

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What do you mean by potential gradient

Posted by Vanya Singh 6 years, 4 months ago

CBSE > Class 12 > Physics

5 answers

Vinay Ranjan 6 years, 4 months ago

•The potential drop per unit length of potentiometer wire is called potentail gradient.... ••{K=v/i} ••• S.i. unit = v/m

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Gursharn Kaur 6 years, 4 months ago

Potential gradient is the difference in potential between two points ∆V= V1- V2

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Pragati Gola 6 years, 4 months ago

V/l

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Aman Kumar 6 years, 4 months ago

Potential gradient is defined as potential drop per unit length on the potentiometer wire..It is denoted by lambda[.•.lambda=Vab/L ....](where ,Vab =potential diff. of the potentiometer wire and L = length of the wire...)

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Neelam Kari Kumari 6 years, 4 months ago

dv/dr know as potential gradient

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Dimensions formula trik

Posted by Ramakant Jatwar 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Aashish Sharma 6 years, 4 months ago

This is the right one ... Easy learning

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Gursharn Kaur 6 years, 4 months ago

U must know the formila for which u are going to calculate the dimensional formula As if u want to calculate the dimensional formula for force = ma So, m= M And, accerlation = LT-2 So formula = MLT- 2

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Ncert important topic coming in railway paper

Posted by Ravi Das 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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a cell has an emf of 1.68 v and internal resistance of 350 ohm. what will be the maximum current drawn from cell

Posted by Angel Wafa 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Pankaj Chadda 6 years, 4 months ago

I=1.68/350

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Samina Khan 6 years, 4 months ago

0.0048.... As I=V/R

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What is dimentions of stress?

Posted by Saloni Kumari 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Gursharn Kaur 6 years, 4 months ago

Stress= pressure= force/ area

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Aman Kumar 6 years, 4 months ago

ML^-1T^-2

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Light year is unit of,?

Posted by Saloni Kumari 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Gursharn Kaur 6 years, 4 months ago

Distances

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Pankaj Chadda 6 years, 4 months ago

Long distances

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꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 4 months ago

It is unit of distance.

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What do you understand by scalar and vector quantities?

Posted by Saloni Kumari 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Vinay Ranjan 6 years, 4 months ago

Vector quantity which obey vector law of addition ... Ø® Scalar quantity which not ❌ obey vector law of addition...

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Gursharn Kaur 6 years, 4 months ago

Scalar mein direction nhi hoti par vector mrin hoti hai

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Samina Khan 6 years, 4 months ago

Vector quantities are those quantities which have both magnitude and direction and also obey the law of vector addition while scalar quantities only have magnitude

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What is the working principle of logic gates?

Posted by Ayushi Dave 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 4 months ago

Logic gate receives two incoming electric currents, compares them, and sends on a new, outgoing electric current depending on what it finds. There are quite a few different types of logic gate, viz AND, OR, NOT, XOR (Exclusive Or), NAND (NOT AND), and NOR (NOT OR).

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What is the easy way to do expressions

Posted by Keshav Kamboj 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Which thing cut by the syllabus

Posted by Ravi Das 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

꧁≪Mämƭå ℭℏ۝ᑌĎℎàℜÿ? 6 years, 4 months ago

In physics last chapter is deleted. In chemistry solid state and group 15 from p block elements are deleted. In english novels are deleted and new chapters in vistas -- the third level and journey to the end of earth are added.

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Two electric charges of 5micro columb and 20micro columb are placed 6cm apart in air . Locate the position of the point on the line joining them . Where the electric field is zero

Posted by Nehal Choudhary 6 years, 4 months ago

CBSE > Class 12 > Physics

4 answers

Nehal Choudhary 6 years, 4 months ago

Answer is 2cm from 5micro columb

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Gursharn Kaur 6 years, 4 months ago

No, correct answer is 0.03m

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Gursharn Kaur 6 years, 4 months ago

No the correct answer is 0.03m

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Nancy Rajput 6 years, 4 months ago

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Sir which books to prefer in physics

Posted by Smruti Panda 6 years, 4 months ago

CBSE > Class 12 > Physics

10 answers

Aman Kumar 6 years, 4 months ago

Yaah...

3Thank You

Priya Dharshini ? 6 years, 4 months ago

Tnq aman..☺ i hope u r also back now after a month...

2Thank You

Aman Kumar 6 years, 4 months ago

U can also take arihant.....and wlc back priya?

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Priya Dharshini ? 6 years, 4 months ago

Sl aroro and 10 years sample paper of arihant for all the subjects..... it is really a v.good book

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Yamima Rai 6 years, 4 months ago

Arihant all in one...its good all the previous question are solved

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Gursharn Kaur 6 years, 4 months ago

Pradeep

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Yakshi Baliyan 6 years, 4 months ago

S L Arora

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Ďãřşháñăã Yadav ? ? ? 6 years, 4 months ago

there are many but most preferable is SL for cbse preparation.

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Nehal Choudhary 6 years, 4 months ago

ABC

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Aman Kumar 6 years, 4 months ago

S L Arora...

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What is optical fibre and what are its uses , working principle and also construction

Posted by Aryanika Agnihotri 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Abhinav Singh 6 years, 4 months ago

https://en.m.wikipedia.org/wiki/Optical_fiber

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The velocity of light in a liquid is 1.5 X 10^8 m/s and in the air it is 3 X 10^8 m/s , if a ray of light passes from this liquid into air. Calculate the values of critical angle ? Plzzzz koi isko solve karke batayo ?

Posted by Shagun Sharma 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Shagun Sharma 6 years, 4 months ago

Nhi ans: 30 hai ☺️

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Aman Kumar 6 years, 4 months ago

Kya answer 2 hai???

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What is the specific heat capacity of water?

Posted by Janardhan Ladke 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Sandeep Kumar 6 years, 4 months ago

Specific heat is defined as the amount of heat one gram of a substance must absorb or lose to change its temperature by one degree Celsius. For water, this amount is one calorie, or 4.184 Joules.

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Hritik Kumar 6 years, 4 months ago

Specific heat capacity is defined as the raise the temperature of one degree

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Can centre of mass of a body lies outside the body?

Posted by Rishita Shishir ?✏ 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Sudarshan Sharma 6 years, 4 months ago

Yes for example a L- shaped frame

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Sandeep Kumar 6 years, 4 months ago

In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe.

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Aman Kumar 6 years, 4 months ago

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ABCD is a square of side 5m . Charges of +50 C, -50 C. And +50C are placed at A,Cand D respectively fibd the resultant electric field at B

Posted by Abhinav Saini 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Ďãřşháñăã Yadav ? ? ? 6 years, 4 months ago

Electric field due to A ➡️ EA =k ×50/5 ²__________ Electric field due to B ➡️ EB =k×50/5²_____ E (net) ➡️ sqrt of EA²+EB² which give ➡️ underoot 2 ×k×50/5²______ Electric field due to charge at C.________ Ec➡️ k×50/5²____ E'(net) ➡️ sqrt of E(net) ²+Ec²= by solving this u will get ur answer 27×10^9 v/m. along AB.

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Color coded resistor trick

Posted by Ravi Das 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Sia ? 6 years, 4 months ago

Here's one mnemonic "Bright Boys Rave Over Young Girls But Veto Getting Wed. Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White <=> 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
Best method to memorize is - B.B. Roy of Great Britain Veto getting wed. Alternatively, most of the colors are those from the traditional rainbow. Black is 0 (as in 'nothing'), Brown is 1, then Red through Violet, and finally Gray and White are 8 and 9.
The multiplier band goes by the same code and can be read as "followed by N zeros", plus Gold for "divide by 10" and Silver for "divide by 100".
Tolerances are something of a mess: Brown and Red are 1% and 2% (you usually spot them because they have an extra significant digit), Gold and Silver are 5% and 10%, and 20% doesn't even get a tolerance band (you will rarely, if ever, come across one of these).
To read the whole thing, put the tolerance band at your right, and go like this:"green-brown-red-gold = 5-1-00-5% = 5.1K 5%". You'll get used soon enough, and a bit later you'll be spotting what you want at once. It's also easy to classify them by decade: red is Ks, orange is 10Ks

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⚡?Chinmay?⚡ ⚡?Rathore?⚡ 6 years, 4 months ago

In the up⬆️ answer there is no violet colour so the trick is B B R O Y of Great Britian had Very Good Wife. The answer writen in the most preferred reference SL ARORA

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Ayush Yadav 6 years, 4 months ago

BB ROY GREAT BRITAIN HAS GOOD WIFE

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What is the resistivity of a carbon resistor having two rings one black and one white?

Posted by Ankit Sinha 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 4 months ago

The resitivity of the resistor will be 9 ohms.

The first stripe is black, which means the leftmost digit is a 0.
The second stripe is white, which means the next digit is a 9.

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A concave mirror has a radius of curvature of 30cm.How far must it be placed from a small object in order to give a five time magnified virtual image

Posted by Mohd Basit 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 6 years, 4 months ago

Given ;
R = -30 cm
f = -15 cm
m = -v/u
5 = -v/u
5u = -v
Using mirror formula;
{tex}\frac 1f =\frac 1v + \frac 1u{/tex}
{tex}\frac {1}{-15} =\frac {1}{-5u} + \frac 1u{/tex}
{tex}\frac {1}{-15} =\frac {-1+5}{5u}{/tex}
{tex}\frac {1}{-3} =\frac {4}{u}{/tex}
u = -12 cm
Hence the mirror should be placed 12 cm away from the cavity to produce 5 times magnification.

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Sir NCERT ka physics book ka language thoda hard me likha gya so usko padhne me problem aata hai but mai usko manage kar luga but only NCERT Book padhne se aur uska questions solve kar lene par exam ka preparation ho gya ga physics ke exam me numerical sb NCERT se hi ayega yadi NCERT Book pahdne se exam ki preparation ho gyaga to mai jarur se NCERT Book hi paduga Please reply sir

Posted by Amarjeet Yadav 6 years, 4 months ago

CBSE > Class 12 > Physics

4 answers

Sia ? 6 years, 4 months ago

We don't think that NCERT is sufficient for CBSE class 12th Physics preparation. We suggest you to use some other additional reference book like U-Like, or We can suggest you a very good book its by S.L. Arora by Dhanpat Rai Publication.

2Thank You

Manika Gupta 6 years, 3 months ago

I think u should first complete ur ncert after that went to reference books

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Priya Dharshini ? 6 years, 4 months ago

U need to do ncert solved and unsolved questions must. But that will never be enough for ur boards so do sl arora , arihant or any reference book

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Aman Kumar 6 years, 4 months ago

Don't worry friend, tum sabse phele ncert padho....uske baad hi koi dusri book ko dekho...haan, ncert se 80% preparation ho jata h...its a base...haan but dusre reference book ko bhi padh lena ager tumhara maan kare toh

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If a vector starting from origin makes an angle theta from x axis then angle from y and z axis must be greater or equal to 90 - theta . Explain and prove

Posted by Manjima Biswas 6 years, 4 months ago

CBSE > Class 12 > Physics