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Mathematical form:
The internal energy of the system can be changed in two ways:
(i) by allowing heat to flow into the system or out of the system,
(ii) by work is done on the system or work done by the system.
Let us consider a system which undergoes a change from one state to another. Let the initial internal energy of the system be U₁. Now if a system is supplied q amount of heat, then internal energy of the system increases and becomes U₁ + q.
If work (w) is done on the system, then its internal energy further increases and becomes U₂. The energy U₂ is the energy in the final state.

The above expression is the mathematical form of the first law of thermodynamics. w includes all kinds of work such as pressure-volume work, electrical work etc.
If the work is done in the above process is only pressure-volume work,

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What is sensitivity ?

Posted by Ranjith Good 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Gursharn Kaur 6 years, 4 months ago

Sensitivity of a galvanometer organza voltmeter may be defined as the least count which shows the maximum deflection on account of the current

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Value of Force is negative its possible or not

Posted by Jai Dev Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

4 answers

Vikas Semwal 6 years, 4 months ago

No value of force can't be nagative, only direction may be

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Gursharn Kaur 6 years, 4 months ago

As the force is a vector quantity the direction of the force applied make change the value of a force which may be positive or negative

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Shubham Sain 6 years, 4 months ago

Yes it is possible because force is vector quantity. And if force applied opposite to motion then it take as negative force

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Sunmeet Kaur Sachdeva 6 years, 4 months ago

It is possible if force is applied on Opposite direction ↔

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If the electron drift speed is so small and the electrons charge is very small how we till obtain a large amount of current in the conductor

Posted by Aastha Bajiya 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Vikas Semwal 6 years, 4 months ago

Dude electron not travel, only passes and vibrates each other, means electron transfers the energy not themselves

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Gursharn Kaur 6 years, 4 months ago

As we know that the formula of current is I is equal to a n e v d that means the amount of current is directly proportional to the area of the conductor through which the electrons are passing and number of the electrons passing so to obtain a large amount of current we need to increase the area and number of electrons passing through the conductor

1Thank You

Xyz Yzx 6 years, 4 months ago

Because conductors has large no. Of free electrons nearly 10^28 /m^3 Therefore cumulative of so many electron results in large amount of current in the conductor

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If other factor remain constant, which of the following combination of number of turns per 20 cm and electric current produce the weakest respectively in a solenoid produce the weakest electromagnet?

Posted by Sachin Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Adrija Ghosh 5 years, 3 months ago

hiii

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Who's pole compass needle show copmpass pole or earth pole

Posted by Mad Boy Raja 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Gursharn Kaur 6 years, 4 months ago

not able to get your question

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. Explain the physical process on the basis of which the r.m.s value of AC is defined.Derive the expression for r.m.s. value of an alternating voltage . How does the value of capacitive reactance of a capacitor change with the frequency of the applied alternating e.m.f across it.

Posted by Samir Sheikh 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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Is Cbse 2019-20 date sheet is released

Posted by K K 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Xyz Yzx 6 years, 4 months ago

Yes from 15 February onwards

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Raman Brar 6 years, 4 months ago

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Write down the application of spherical mirror

Posted by Tofik Malik 6 years, 4 months ago

CBSE > Class 12 > Physics

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an electric dipole is placed inside a conducting shell mark the correct statement a. the flux of the electric field through the shell is zero b. the electric field is 0 at every point on the shell c. the electric field is not zero anywhere on the shell d. the electric field is zeroon a circle on rhe shell

Posted by Abhinay Katoch 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Abhishek Yadav 6 years, 4 months ago

Electric Field inside a hollow sperical condecting cell is0

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How can we show that electric dipole doesn't show any translators motion in uniform electric field?

Posted by Swati Patil 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Nittin Sihmar 6 years, 4 months ago

Since the electric dipole is held in a uniform electric field no net force is acting on the dipole. Force due to -q is -qE and force due to +q is qE.

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Abhishek Yadav 6 years, 4 months ago

Dua to two force not act at dipole

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Whichof the following is wrong? Resistivity of a conductor is

Posted by Prince Chaudhary 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Ravi Yadav 6 years, 4 months ago

Inverse of conductivity

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How we get 0.636 as mean average value of A.C

Posted by Manya Sharma 6 years, 4 months ago

CBSE > Class 12 > Physics

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two coil of wire a and b are placed mutually perpendicular . when a current induced is changed in any one coil. will the current induced in another coil ?

Posted by Tanisha Jaiswal 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Mp? Mp? 6 years, 4 months ago

No because no flux linkage will be there because magnetic field and area vector become perpendicular to each other thus BA cos theta becomes zero as theta is 90

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how many hours will be available for cbse board exam 2019-2020....

Posted by Pooja Bhakar 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Ravi Yadav 6 years, 4 months ago

3 hours as of last time

1Thank You

Div¥@N$Hi P@M@® 6 years, 4 months ago

3 hours

1Thank You

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Which colour is on the top of primary rainbow

Posted by Raman Brar 6 years, 4 months ago

CBSE > Class 12 > Physics

5 answers

Ujjwal Moral 6 years, 4 months ago

Red colour We have to see vibgyor fron bottom

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Sunmeet Kaur Sachdeva 6 years, 4 months ago

Violet as in vibgyor

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Ravi Yadav 6 years, 4 months ago

Red color

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Vanya Singh 6 years, 4 months ago

Red colour on top and violet colour at bottom

2Thank You

Vikas Semwal 6 years, 4 months ago

Violet

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Calculate the rms value of the current in ac circuit containing a capacitor of 40uf and resistor10 ohm in series . the power supply in circuit is rated 230 v 50 hz

Posted by Ritik Chaubey 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

1 KWH equals to how many joules

Posted by Deepesh Yadav 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Manya Sharma 6 years, 4 months ago

3.6×10^6joules

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Deepesh Yadav 6 years, 4 months ago

3.6×10^6 joules

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I need a paper to2020

Posted by Umesh Sagar 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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Please tell the question 9 of chapter current electricity NCERT class 12th

Posted by Akash Pandey 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Ravi Yadav 6 years, 4 months ago

Do practice of this kind of questions many time our teacher is also not able to solve this kind of question

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Manya Sharma 6 years, 4 months ago

By using kirchoff's 2nd rule we can get its answer Total current =10/17Ampere

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From where we can practice fill ups

Posted by Tanu Sharma 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Ravi Yadav 6 years, 4 months ago

Exampler

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Vikas Semwal 6 years, 4 months ago

Together with

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Why intensity of light remains half when pass through Polaroid

Posted by Ron Vineetahuja 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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What is the SI unit of current density

Posted by Melvin Mathew 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Ujjwal Kashyap 6 years, 4 months ago

Ampere per metre square

2Thank You

Manish Verma 6 years, 4 months ago

Ampere per metre square

2Thank You

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Which wave is used for treatment of cancer

Posted by Bhupender Choudhary 6 years, 4 months ago

CBSE > Class 12 > Physics

4 answers

Ravi Yadav 6 years, 4 months ago

Radoiactive is used for both cure and effect

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Manya Sharma 6 years, 4 months ago

X-Rays ,gamma rays and charged particles are used for cancer treatment.

0Thank You

Shivam Chaurasia 6 years, 4 months ago

Uv rays

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Raman Brar 6 years, 4 months ago

Gamma rays

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I have to submit a project on capacitors. And i dont know what to add in its types. Suggestions please

Posted by Rea Rea 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Angad Shah 6 years, 4 months ago

Porn dekh ke

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Swati Patil 6 years, 4 months ago

There are various types of capacitors like cylindrical, parallel plate, spherical, etc.

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Could u pls tell the weightage of every chapter & blue print too?

Posted by Prakriti Panwar 6 years, 4 months ago

CBSE > Class 12 > Physics

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Does we need to prepare anything from other refreshers or go thorough with ncert

Posted by Abby Ohhh 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Abby Ohhh 6 years, 4 months ago

Thanks

1Thank You

Abhishek Kumar 6 years, 4 months ago

Hey, srishti You not need to go through any book other than NCERT AND EXEMPLAR and previous year paper.

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How many experiments should be written in record note?

Posted by R Meera Raghunaathan 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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Why the electric field lines does not pass through a conductor?????

Posted by Dj Sh 6 years, 4 months ago

CBSE > Class 12 > Physics

3 answers

Ravi Yadav 6 years, 4 months ago

Bcz in conductor q is on the surface not on its centre in centre q =0

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Ɽøⱨł₮ ₲Ʉ₱₮₳ 6 years, 4 months ago

After keeping a conductor under the influence of an electric field, the free electrons of the conductor will arrange themselves such a way so that they can cancel any field line inside the conductor and make the electric field 0 inside it. ... Otherwise, electrons could not move through the wire to make a current

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Priya Singh 6 years, 4 months ago

Because the electrons within the conductor are free to move around and can thus fully absorb all the energy from the electromagnetic wave

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