Properties of charge - class-XII

The total charge of electrons removed from the coin would be equal to the positive charge acquired by the coin.

Q=ne, according to Quantum nature of charge, in nature charge always occurs as an integer multiple of electronic charge i.e. $\displaystyle Q=\pm ne$

Inside the cavity of charged measure sphere net electric field is non zero constant.

For a charge to experience no force, the electric fields from the two charges must be equal and opposite. Setting k(2)/x^2 = k(1)/(10-x)^2 leads to 2(10-x)^2 = x^2, which simplifies to sqrt(2)(10-x) = x. Solving for x gives x = 10*sqrt(2)/(1+sqrt(2)) approximately 5.858 cm.

Thermal neutrons are neutrons that are in thermal equilibrium with their surroundings, typically having kinetic energies around 0.025 eV, which is well below 1 eV.

The statement is true as electrons can be transferred from one body to the other,  thereby changing the number in the system.  

Quantisation of Charge means that we say something has some charge , we mean by that that how many times the charge of electrons it has.  Because  whole charge is associated with an electron.

The charge of an electron is, $e=1.6\times { 10 }^{ -19 }C$.

The minimum possible charge is equal to the charge of the electron.That is, $e=1.6\times { 10 }^{ -19 }C$.
The electron is a subatomic particle, symbol e, with a negative elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure.

The SI unit of electric charge is Coulomb, One coulomb is equal to about $6.242\times { 10 }^{ 18 }e$. 
One coulomb is defined as the quantity of charge which will pass through the cross section of an electrical conductor while one ampere current is flowing through the conductor in one second. Electric charge is denoted by Q.

Answer is C.

Electron charge, fundamental physical constant expressing the naturally occurring unit of electric charge, equal to 1.6021765 1019 coulomb. In addition to the electron, all freely existing charged subatomic particles thus far discovered have an electric charge equal to this value or some whole-number multiple of it.
Hence, the charge of the electron is $-1.6\times { 10 }^{ -19 }C$. The negative sign is due to the negative charge of electrons.

Any segment of conductor is electrically neutral.
There are fixed positive ions already present that will neutralize the negative charge of the electrons.
No segment serves as the source/sink of charge

Electric charge is due to the loss or gain of electrons.
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as cations; those with a negative charge are anions.

Answer is C.

The formula for quantisation of charge is given as q=ne.
where, q is the amount of charge in Coulumbs, n is the number of charges and e is the charge on the electron.
In this case, q=4/25 C
So, e = $1.6\times { 10 }^{ -19 }C$.
n can be calculated as n=q/e = $\frac { 4 }{ 25 } \times [\frac { 1 }{ 1.6\times { 10 }^{ -19 }C } ]\quad =\quad { 10 }^{ 18 }$ which is the number of electrons.
Hence, 4/25 Coulomb of charge contains ${ 10 }^{ 18 }$ electrons:.

The capacity of the metallic sphere is proportional to the radius. It does not matter whether it is solid or hollow. Therefore the hollow sphere will hold same charge as the solid sphere.

The word quantised means any quantity is an integral multiple of a minimum value and cannot have any value equal to decimal multiples.

Charge on a body is always $\displaystyle \pm e$, $\displaystyle \pm 2e$, $\displaystyle \pm 3e$. It can't be in fraction of e i.e 1.5e, 0.9e or -1.2e. The electronic charge is the minimum possible charge.

Charge on an electron is -e. SInce, an atom can lose or gain an integer number of electron, so charge on an will be an integer multiple of e.

Charge on a body is always $\displaystyle \pm e$, $\displaystyle \pm 2e$, $\displaystyle \pm 3e$. It can never be in fraction of e. i.e. 1.5e or -1.2e.

Since the charge is placed at the centre of the cube, so the electric flux lines move out equally from all sides of the cube. Thus the electric flux emerging from the cube is equal to $\dfrac{q}{\varepsilon _0}$.

Photon is the elementary quantum of energy.

Bulbs in street lightning are all connected in parallel.

For testing appliances, the wattage of test lamp should be high, as higher watt lamps have lower resistance and will not blow up the testing appliacnces.

The additive nature of charge is one of the property of electric charge. The entire electric charge of a system is equal to the algebraic sum of electric charges located in the system. This is the law of superimposition of electric charge.

As charge is quantized. 

Total charge must be quantized i.e., it must be a multiple of charge of $e^-$ $=$ $1\cdot 6\times 10^{-19}C$
as $4\times (1\cdot 6\times 10^{-19})=6\cdot 4\times 10^{-19}$
this charge is possible ($4e^-$)

We know that charge must be integral multiples of $1\cdot 6\times 10^{-19}C$ as charge of
one electron $=1\cdot 6\times 10^{-19}C$
We cannot get any charge less than $1\cdot 6\times 10^{-19}$  $\therefore$ we cannot get $9\cdot 6\times 10^{-20}C$

The charges from one body can be transferred to another body but the total charge of a system remains constant.

Charge is an integral multiple of e, minimum charge possible is equal to e which is $1.6 \times 10^{-19}$ C.Hence correct answer is option B.

Given that $\phi $, no. of field lines $=1000$

After redistribution, charges on them will be different, but they will acquire common potential i.e.

The density of field lines shows the strength of field, and hence reveal the information about the magnitude of charge that is quantity of charge on the source.

$\begin{array}{l} U=qV \ =8\times { 10^{ -19 } }\times 200J \ =\dfrac { { 8\times { { 10 }^{ -19 } }\times 200 } }{ { 1.6\times { { 10 }^{ -19 } } } } eV \ =1000ev \ Hence,, the, option, B, is, the, correct, answer. \end{array}$

Original force$,$

The law of conservation of charges states that electric charge can neither be created nor destroyed.
Hence the net quantity of electric charge of the universe is always conserved. 

The formula for quantization of charge is given as q=ne.
where q is the amount of charge in Columbu's, n is the number of charges and e is the charge on the electron.
In this case, q=4/25 C
So, e = $1.6\times { 10 }^{ -19 }C$.
n can be calculated as n=q/e = $\frac { 4 }{ 25 } \times [\dfrac { 1 }{ 1.6\times { 10 }^{ -19 }C } ]\quad =\quad { 10 }^{ 18 }$ which is the number of electrons.
Hence, 4/25 Coulomb of charge contains ${ 10 }^{ 18 }$ electrons.

A, B and C are correct. 

1 electron carries a charge of $1.6 \times 10^{-19}$ coulomb 

Charge on an electron $= 1.6 \times 10^{-19}$coulomb

When ressitance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will increases because the resistance of wire decreases due to decrease in length of it. 

When circuit has high inductance then sparking occurs.

When a dc current is passed through water, the electrolysis of water molecules $(H _{2}O)$ takes place i.e, water gets split into hydrogen and oxygen gases. The bubbles are these gases escaping.

Let the total electronic charge be n

According to law of conservation of charge, the net charge inside an isolated system is conserved. 

Here, $n(-e)=Q=-1C$ or $n=1/e=\dfrac{1}{(1.6\times 10^{-19})}=6.25\times 10^{18}$

The net charge of the given system is $Q=Q _1+Q _2+Q _3=(5+3-2)\mu C=6\mu C$

Charge separation is the process of exciting an electron in an atom to a higher energy level and then making it leave the atom to a hereby electron acceptor thus creating charged particle.

Charge removed=$-e\times n=-1.6\times 10^{-19}\times 5\times 10^{12}=-8\times 10^{-7}=-0.8\mu C$

The transfer of electrons from one body to other leads to charging of bodies. It is found that charge on any body is always equal to integral multiple of charge on electron. This property of charge is known as Quantisation of electric charge according to which, $Q=ne$
$Q=$ total charge transferred
$n=$ number of electrons transferred
$e=$ charge on one electron
$n=1, \pm 2.....$ and so on.

Charge has to be an integral multiple of electronic charge e.

Any charge exists in discrete lumps or packets of a certain minimum charge e where e is the charge of an electron. According to quantization of charge, the charge on a body can be only an integral multiple of charge on the electron i.e., $q = ne$ where n = 1, 2, 3 and $e=1.6\times { 10 }^{ -19 }$ C.

 Due to rubbing, heat is generated which supplies energy for removal of electrons. As the work function of the glass rod is smaller than the silk cloth, it easily loses electrons to the silk cloth.

$q=ne$
$\therefore n=\dfrac {q}{e}$
Given $q=1C$
$e=-1.6\times 10^{-19}C$
$n=\dfrac {1C}{1.6\times 10^{-19}}$
$6.25\times 10^{18}$ or $62.5\times 10^{17}$

$d=1A$

Charges are acquired by either gain or loss of electrons .

Charge on each electron$=e$