Tag: static electricity

Quizzes (14) Questions (148)

Questions Related to static electricity

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

A polythene piece rubbed with wool is found to have a negative charge of $3.6\times 10^{-7}C.$ Calculate the number of electrons transferred from wool to polythene:

  1. $6.25\times 10^{18}$
  2. $2.25\times 10^{12}$
  3. $2.05\times 10^{-18}$
  4. $2.18\times 10^{10}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$n=\dfrac {q}{e}=\dfrac {-3.6\times 10^{-7}C}{-1.6\times 10^{-19}C}$

$=2.25\times 10^{12}$
$\therefore 2.25\times 10^{12}$ electrons are transferred from wool to polythene.

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

A sure test of electrification is:

  1. attraction

  2. repulsion

  3. friction

  4. induction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Repulsion is the sure test of electrification.
Note: If two bodies are electrified (i.e., charged they can either attract or repel). If they are:
(a) attracted: this is not only possible by electrification but can also be due to the attraction of an uncharged body with charged body.
(b) repulsion: repulsion is possible only when both objects are charged oppositely.

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

When a glass rod is rubbed with silk, both become charged due to:

  1. migration of protons

  2. exchange of electrons and protons

  3. migration of electrons

  4. migration of neutrons
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a glass rod is rubbed with silk cloth glass rod becomes positively charges while silk cloth becomes negatively charged. This is due to transfer or migration of electrons from glass rod to silk cloth.

Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

A glass rod when rubbed with silk cloth acquires a charge $1.6 \times 10^{-13}  C$. What is the charge on the silk cloth?

  1. $-1.6 \times 10^{-19} C$
  2. $1.6 \times 10^{-13} C$
  3. $-1.6 \times 10^{-13} C$
  4. $1.6 \times 10^{-19} C$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a glass rod is rubbed with silk, both gets electrified due to charging by friction. Given, glass rod acquires positive charge $=1.6\times 10^{-31}\, C$. So silk acquires equal and opposite charge as that on glass rod. Hence the answer is $-1.6\times 10^{-13}\, C$.

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

A gold coin has a charge of $+10^{-4} C$. The number of electrons removed from it is:

  1. $10^6$
  2. $625 \times 10^{12}$
  3. $1.6 \times 10^{-25}$
  4. $1.6 \times 10^{13}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

Thus, $10^{-4}C=n\times 1.6\times 10^{-19}C$
$\implies n=625\times 10^{12}$

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

A parallel late condenser consists of two circular plate each of radius $8cm$ separated by a distance of $2mm$. It is charged by an external source, with a constant charging current of $0.15$ A. The displacement.curcent is

  1. $0.10A$
  2. $0.15A$
  3. $0.20A$
  4. $0.30A$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Displacement current inside a capacitor is equal to the conduction current charging the capacitor plates. Since the charging current is given as 0.15 A, the displacement current is also 0.15 A.

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

Choose best option about cavity for a charged metallic sphere: 

  1. Net field inside the cavity is zero

  2. Net field inside the metal is non-zero constant

  3. Potential inside the metal is constant

  4. Potential outside metal is constant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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

$\therefore $ Option $A$ is correct.

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

Two charges 2$\mathrm { uC }$ and 1$\mathrm { \mu }C$ are placed at adistance of 10$\mathrm { cm }$ . The position of the third charge from2$\mu \mathrm { C }$ between them so that it does not experience any force

  1. $7cm$
  2. $2cm$
  3. $5.858cm$
  4. $8cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

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

An infinite number of charges each equal to q coulomb are placed along x-axis at x 1, x = 2, x= 8. so on the potential and electric field at x =0 due to this arrangement is

  1. $\dfrac { q } { 2 \pi \varepsilon _ { 0 } } , \dfrac { 3 q } { 4 \pi \varepsilon _ { 0 } }$
  2. $\dfrac { q } { 2 \pi \varepsilon _ { 0 } } \cdot \frac { q } { 3 \pi \varepsilon _ { 0 } }$
  3. $\dfrac { 2 q } { \pi \varepsilon _ { 0 } } , \dfrac { q } { 3 \pi \varepsilon _ { 0 } }$
  4. $\dfrac { q \varepsilon _ { 0 } } { \pi 2 } , \dfrac { q E _ { 0 } } { 3 \pi }$
Reveal answer Fill a bubble to check yourself
B Correct answer