Basic Properties of Electric charge notes with video explaination is prepared and uploaded for reference by academic team of expert members of Param Himalaya.
Basic Properties of Electric charge :
1. Charges are of two Types, positive and negative.
2. Like charges repel each other and unlike charges attract each other.
3. Positive and negative charges tends to cancel each other.
4. Additivity of Electric charge :
Electric Charge is additive means total charge on an extended body is the algebraic sum of charges in different regions of the body.
q = q1 + q2+.....qn
Example : A system has two charges qA = 2.5 × 10-7 C and qB = - 2.5 × 10-7 C , what is the total charge on the system ?
Solution :
Total Charge on the system
q = qA+qB
q = (2.5×10-7 )+ (- 2.5 × 10-7 C) = 0
Hence , the given system is neutral.
5. Conservation of Electric Charge :
According to the law of conservation of Electric charge , net electric charge ( algebraic sum of positive and negative charges ) in an isolated system remains constant.
Charges can neither be created nor be destroyed in an isolated system.
Example :
(i) A glass rod rubbed with a piece of silk cloth get positively charged , whereas the piece of silk cloth becomes negatively charged. The positive charge on glass rod after rubbing is equal to the negative charge on silk cloth. Before rubbing ,
total charge on the system = positive charge on glass rod + negative charge on the silk cloth = zero
Hence , electric charge is conserved .
\[(ii) _{92}^{238}\textrm{U}\;decays\;by\;emitting\;\alpha -particle\;\]\[(_{2}^{4}\textrm{He}\;nucleus),\;to\;give\;thorium\;( _{90}^{234}\textrm{Th})\]
\[_{92}^{238}\textrm{U} \rightarrow\; _{90}^{234}\textrm{Th} \;+\;_{2}^{4}\textrm{He}\]
\[Number\;of\;elementary\;charges\;before\;decay\; (on\;_{92}^{238}\textrm{U}) = 92\]
\[\gamma \rightarrow e^{+}+e^{-}\] hamara
6. Quantization of Electric Charge :
Quantization is the property of an electric charge by virtue of which any charged body can have charge which is integral multiple of the basic or elementary charge 'e'.
q = ne
Where n = 1,2,3,4,5....
e = elementary charge = 1.6×10 -19 c
Cause of quantization of Electric charge : Electrons are always transferred in integral values from one object to another object.
7. Invariance of Electric charge :
Magnitude of charge on a body does not vary , whatever may be the speed of the body . In other words , charge on an object is independent of the speed of the objects.
Charge on a body at rest = Charge on a body in motion
q ( at rest ) = q ( in motion )