Define the following and give their mathematical expressions: i] Electric Current [ii] One ampere [iii]Electromotive force [iv]Potential difference [v] One volt [vi] Resistance [vii]One ohm [viii]Resistivity [ix]Conductance [x]Conductivity
Answers
Answer:
Explanation:
1. Electric current (l): is defined as the time rate of flow of electric charge along a conductor.
I=Q/t
Q is the quantity of charge measured in Coulomb, ‘t’ is the time in second . I is the current in Ampere(A).There are submultiples of Ampere
1mA = 10-3A
1μA = 10-6A
2. Electromotive force: Electromotive force is defined as the total work done in driving one coulomb of electricity round a closed circuit or the total energy per coulomb obtained from a cell or battery.
E.m.f=work/charge
Electromotive force can also be defined as the potential difference across the terminal of a cell when it not delivering current to an external circuit or the potential difference across the terminal of a cell when it is in an open circuit.
3. Potential difference ( V): The potential difference between any two points in an electric field is defined as the work done in moving a positive charge of 1 coulomb from one point in the electric field to another. Potential difference is measured in volts.
Voltmeter is used to measure potential difference.
V=work/charge
4. Resistance: This can be defined as the opposition to the flow of charges (electrons) or current. Its S.I unit is Ohm. It is measured using Ohmmeter.
Explanation:
work done i moving a positive charge of 1 coloumb from 1 point in electric field to another