Flag Electrostatics> A charge Q is divide intointo parts and t...
question mark

A charge Q is divide intointo parts and then they are placed at a fixed. The force between the two charges is always maximum when charges are

Atharva wagh , 4 Years ago
Grade 11
anser 2 Answers
Arun

Last Activity: 4 Years ago

 

let parts are sepereted at a distance of d

so repulsion force F= k q(Q-q)/d2

     here Q and d are constant so for maximum force differentiate the force w.r.t q

 dF/dq = k/d[Q -2q]

 for maximum force dF/dq=0

                             Q-2q=0

                              Q/q =2

Vikas TU

Last Activity: 4 Years ago

Dear student
The above ans is incorrect , Please follow this  
Let q1 = qand q2 = Q-q 
r  be the distance or separation between them 
The force of repusion between them is 
F = k (Q-q)q/r^2 
Differenciating F with respect to q and setting it to zero will give us extreme force.
dF/dq = 0 
so, q/Q = 1/2 
For this value q/Q the force is maximum .
The force will be maximum if the second derivative of F is less than 0 
d^2F /dq^2= -2k/r^2 which is less than 0.
Thus the force of repulsion is maximum when q=Q/2 
so , q1 = Q/2 an q2 = Q/2 

Hope this helps 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...