Current electricity Flashcards
What is charge?
The excess or deficit amount of electrons in a body is said to be charge.
What is the unit of charge?
coulomb(C) is the S.I unit of charge.
What is the charge on an electron?
- 1.6 x 10^-19 C
Define current.
Current(I) is defined as the rate of flow of charge.
Unit of current.
ampere(A)
Formula for I.
I =Q/T
What is potential(V)?
The potential at a point is defined as the work done per unit charge in bringing a positive test charge from infinity to that point.
Formula for V.
V=Work done/charge
What is potential difference?
The potential difference between two points is equal to the work done per unit charge in moving a positive test charge from one point to the other.
What is resistance?
The obstruction offered to the flow of current by the conductor is called its resistance.
State the Ohm’s law.
According to the ohm’s law the current flowing in a conductor is directly proportional to the potential difference applied across its ends provided that the physical condition and the temperature of the conductor remain constant.
Ohm’s law
V = IR
What are ohmic resistors?
The conductors which obey the ohm’s law. ex: silver, aluminum , copper ,etc.
What are non ohmic resistors?
The conductors which do not obey the ohm’s law. ex: LED, solar cell, transistor, etc.
What are the factors affecting resistance?
- material of the conductor
- length of conductor(directly proportional)
- thickness of the conductor(indirectly proportional)
- temperature of the conductor(directly proportional)
