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Multiple choice physics static electricity properties of charges charge properties of charge

The additive nature of charge can be explained by the 

  1. Law of Conservation of Electric Charge

  2. Law of Quantisation of Electric Charge

  3. Law of Superposition of Electric Charge

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Multiple choice physics static electricity properties of charges charge properties of charge

Fill in the blank.

$1$ Coulomb of charge contains_______number of electrons.

  1. $6.25\times 10^{18}$

  2. $3.125\times 10^{18}$

  3. $6.25\times 10^{12}$

  4. $3.125\times 10^{12}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As charge is quantized. 

Total charge, $Q = ne$
$1$ coulomb $=ne \implies$ $n$ $= \dfrac{1} {1\cdot6\times10^{-19}}$

 
 $n$ $=6\cdot25\times10^{18}$

Multiple choice physics static electricity properties of charges charge properties of charge

A body has a total charge of $6.4\times  10^{-19}$coulomb. It is :

  1. possible

  2. not possible

  3. may or may not be possible

  4. Data insufficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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 ($4e^-$)

Multiple choice physics static electricity properties of charges charge properties of charge

A body has a charge of $9.6 \times 10^{-20}$coulomb. It is :

  1. possible

  2. not possible

  3. may (or) may not possible

  4. Data not sufficient
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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 $9\cdot 6\times 10^{-20}C$

Multiple choice physics static electricity properties of charges charge properties of charge

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

  1. remains Constant

  2. can change

  3. Will increase

  4. will decrease
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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

Multiple choice physics static electricity properties of charges charge properties of charge

If the number of electric lines of force emerging out of a closed surface is 1000, then the charge enclosed by the surface is

  1. $8.854 \times {10^{ - 9}}C$

  2. $8.854 \times {10^{ - 4}}C$

  3. $8.854 \times {10^{ - 1}}C$

  4. $8.854\,C$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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

From gauss law,
$\phi =\dfrac { { Q } _{ inc } }{ { \varepsilon  } _{ 0 } } $
$\therefore \quad 1000=\dfrac { { Q } _{ inc } }{ 8.85\times { 10 }^{ -12 } } $
$\Rightarrow \quad { Q } _{ inc }=8.85\times { 10 }^{ -12 }\times 1000$
                   $=8.854\times { 10 }^{ -9 }C$

$\therefore $  Option (A) is the correct answer.

Multiple choice physics static electricity properties of charges charge properties of charge

Two insulated charged spheres of radii $20cm$ and $25cm$ respectively and having equal charge $q$ are connected by a copper wire and then they are separated

  1. Both the spheres will have same charge $q$

  2. The charge on $20cm$ sphere will be greater than on the $25cm$ sphere

  3. The charge on $25cm$ sphere will be greater than on the $20cm$ sphere

  4. Both have same charge density 
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

$k\frac{Q _1}{r _1}=k\frac{Q _2}{r _2}\Rightarrow\frac{Q _1}{Q _2}=\frac{r _1}{r _2}$
As,
$\sigma=\frac{Q}{4\pi r^2}$
$\frac{\sigma _1}{\sigma _2}=\frac{Q _1}{Q _2}\times \frac{r _2^2}{r _1^2}\Rightarrow \frac{\sigma _1}{\sigma _2}=\frac{r _2}{r _1}$
$\sigma \propto \frac{1}{r}$ i.e. surface charge density on smaller sphere will be more.

Multiple choice physics static electricity properties of charges charge properties of charge

There are $4\times { 10 }^{ 23 }$ atoms in a metal sphere. If one electron is removed from $0.1\%$ of atoms, what will be the charge on the sphere?

  1. $-6.4C$

  2. $64C$

  3. $0.64C$

  4. $-64C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Given, 

$n=4\times 10^{23}\times 0.1$%

$n=4\times 10^{23}\times \dfrac{0.1}{100}=4\times 10^{20}$

$e=1.6\times 10^{-19}C$

The charge is quantised, $q=ne$

$q=4\times 10^{20}\times 1.6\times 10^{-19}=64C$

The electron is negative charge particle.

So,$q=-64C$

The correct option is D.
Multiple choice physics static electricity properties of charges charge properties of charge

The density of field lines surrounding any given object reveal information about the

  1. the nature of charge on the source charge.

  2. the quantity of charge on the source charge.

  3. both A and B

  4. it reveals no information
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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.