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A material in which electrons are tightly bound and cannot move freely at room temperature is called _________.
Insulators are materials that impede the free flow of electrons from atom to atom and molecule to molecule. Examples of insulators include plastics, paper, rubber, glass and dry air.
In contrast to insulators, Conductors are materials that permit electrons to flow freely from particle to particle. Examples of conductors include metals, aqueous solutions of salts (i.e., ionic compounds dissolved in water), graphite, and the human body.
According to the principle of conservation of charge, in closed system:
Therefore, the correct answer is the algebraic sum of charges in any closed system is constant.
A coulomb is the same as:
We know that Current = Charge / Time
Current = Ampere
Charge = Coulomb
Time = Second
1 ampere = 1 coulomb/ 1 sec
So, one coulomb is ampere times second.
When a glass rod is rubbed with silk, it becomes positively charged because:
When the glass rod is rubbed with silk cloth, glass quickly loses electrons, and silk takes electrons out of the glass rod. So after rubbing, the glass rod becomes positively charged and the silk gets a negative charge.
Silk cloths: Negatively charged
Glass rod: Positively charged
Electric charge between two bodies can be produced by:
Example: When glass is rubbed with silk, glass becomes positive while silk becomes negative.
Which of the following methods can be used to charge a metal sphere positively without touching it? Choose the best possible option:
This can be possible by induction, if a negative charge rod is placed near the sphere (at a distance not in touch) then it attracts positive charge inside the sphere towards its side and the negative charges collected on the other side and when the surface of the sphere connected to the earth than the negative charge goes to earth and the sphere remain positively charged.
Since rubbing the metal ball with fur and a piece of silk cloth involves touching, they can not be the correct answer.
Therefore, the correct answer is C.
If an object is positively charged, theoretically the mass of the object ______.
Choose the correct statement:
According to the principle of conservation of charge, the net amount of positive charge minus the net amount of negative charge in the universe is always constant.
Thus, the correct answer is the total charge of the universe is constant.
To make an uncharged object to have a negative charge we must:
To make an uncharged object have a negative charge we must increase negative charge particles in it and this can be done only by adding electrons to particles as electrons have negative charge.
So, the correct answer is to add some electrons.
When conductors are placed in an electric field, their electrons are moved:
When a negatively charged conductor is connected to earth,
Additional Information: Earth is an electric conductor. Earthing is defined as “the process in which the instantaneous discharge of the electrical energy takes place by transferring charges directly to the earth through low resistance wire.” When a charged body is connected to the earth, it becomes electrically neutral.
A negative ion is an atom that ________ electrons.
Therefore, the correct answer is C.
When a hard rubber rod is given a negative charge by rubbing it with wool:
The value of charge on a body which carries 30 excess electrons is:
Here, n = 30
e = -1.6 x 10-19 C
We know that q = n ∗ e
Therefore, q = 30 * (1.6 x 10-19 C)
q = - 4.8 ∗ 10-18 C
The total negative charge in 1 mol of helium (atomic number 2, atomic mass 4) is:
Name the physical quantity whose S.I. unit is JC-1. Is it a scalar or a vector quantity?
How many electrons are present in 1 coulomb of charge?
According to Quantisation of Charge we know that,
Q = ne
Therefore, 1 coulomb of Charge = n * 1.6 * 10-19
⇒ 1/ 1.6 × 10-19 = n
⇒ n = 6.25 × 1018
What does q1 + q2 = 0 signify?
If we have two bodies with charge q1 and q2 on them and we are given q1 + q2 = 0. It means the net charge on the system is zero.
This is possible only if q1 and q2 are equal and opposite.
That is, q1 = +q and q2 = -q or vice versa.
Such that, q1 + q2 = +q + (-q) = 0
A silk cloth rubbed with a glass rod acquire a charge (-1.6 x 10-19) C. Then the charge on the glass rod is:
During rubbing, glass rod acquires + ve charges and silk cloth acquires - ve charges.
The glass rod will have postive charge equal in value to the negative charge lost by the silk.
∴ the charge on the glass rod is + 1.6×10- 19C
Additional Information: When a glass rod is rubbed with silk, glass happens to lose electrons easily and silk grabs them away from the glass atoms. So after rubbing, the glass becomes positively charged and the silk becomes negatively charged. Thus equal but opposite charges are produced on both.
To make uncharged object have a positive charge: