Electric fields
= a region in space where an electric charge experiences a force
The direction of the electric field at a point is the direction that a positive test charge would
move if placed at that point.
Electric field strength
Symbol: E (vector quantity)
(the magnitude of the electric field at a point)
Force acting per unit positive charge at that point
𝐹 𝑘.𝑄
E= or E=
𝑞 𝑟2
Big Q is the first point charge
Small q comes second
E = electric field strength (N.C-1)
F = force (N)
q = charge (C)
Away from positive
Towards the negative
Gravitational field Electric field
Fg = m x g F=qxE
𝐹𝑔 𝐹
g= E=
𝑚 𝑞
Symbol: N.kg-1 Symbol: N.C-1
= a region in space where an electric charge experiences a force
The direction of the electric field at a point is the direction that a positive test charge would
move if placed at that point.
Electric field strength
Symbol: E (vector quantity)
(the magnitude of the electric field at a point)
Force acting per unit positive charge at that point
𝐹 𝑘.𝑄
E= or E=
𝑞 𝑟2
Big Q is the first point charge
Small q comes second
E = electric field strength (N.C-1)
F = force (N)
q = charge (C)
Away from positive
Towards the negative
Gravitational field Electric field
Fg = m x g F=qxE
𝐹𝑔 𝐹
g= E=
𝑚 𝑞
Symbol: N.kg-1 Symbol: N.C-1
