
Ohm's Law
where,
I = current, amp
V = potential difference, volts
R = resistance, ohms
Top
Resistivity
where,
ρ = resistivity or specific resistance,
ohmm
L = length of wire, m
A = crosssectional area of wire,
m^{2}
Top
Conductance (G)
where,
γ = conductivity or specific conductance, mhos/m
Top
Electric Power
where,
P = electric power, watts
Top
Electric Energy
where, E = electric energy, Joules
V = potential difference, Volts
I = Current, Amperes
R = resistance, ohms
t = time, seconds
E = 0.24I^{2}Rt, cal
For Battery
where
Top
Kirchhoff’s Law
(i)
The algebraic sum of all the currents directed towards a junction point
is zero.
(ii)
The algebraic sum of all the voltage rise taken in a specified
direction around a closed circuit is zero.
Series Circuits:
Parallel Circuits:
Coulomb’s Law
The force acting between two charged bodies q_{1}
and q_{2} in air is proportional to the product of
charges and inversely proportional to the square of the
distance between them.
Top
