Electrostatics – one of the most difficult sections of physics. When studying force fields it is important to know about such size as potential which characterizes the field in specifically taken point and to be able to find potential difference, i.e. voltage.
It is required to you
- sheet of paper, handle
Instruction
1. Before understanding that such voltage and as to calculate it, it is necessary to get acquainted with a number of concepts.
2. According to definition, voltage between two points appears when in one of them there is a surplus of electrons in relation to another. On the charge the particles can be negative "?" and positive "+". Heteronymic particles will be attracted to each other. When in one point there are not enough electrons, around it forms the positive field. Than more this shortage, that stronger sex. Respectively, when in other point electrons in surpluses, the particle seeks to give them, forming around itself the negative field. Thus two potentials which seek to exchange electrons turn out. Until it occurred, between them there is tension, i.e. potential difference.
3. Proceeding from the aforesaid, it turns out that the potential difference equals to the work of electric field which is carried out to move a single positive charge from a point 1 to a point 2. The potential difference is measured in volts (C).
4. To calculate potential difference, use a formula U=Aq where U is required voltage, A is work of electrostatic field, and q is electric charge.
5. The formula is necessary for finding of work. According to it A=-(W2-W1)=-(f2-f1) q=q? t. q – the constant, and f is a potential which you can calculate on a formula f =kqr. k – it is the rigidity coefficient equal 9*10^9 H*м^2/Кл^2. r – this distance from a field source to this point.