Electric Field

Question 1

Define Electric field

Answer 1

Force per unit positive charge

Question 2

Force (on a charge in electric field) Equation

Answer 2

F= q E

E = electric field strength

Question 3

Direction of electric field

Answer 3

Away from positive
Towards negative

(From positive to negative)

Question 4

Define electric potential at a point

Answer 4

Work done per unit positive charge in bringing a small test charge from infinity to the point

Question 5

Electric field strength equation (parallel plates)

Answer 5

E= change in V/ change in d
=V/d

V is pd
d is separation between plates

Question 6

Electric field strength of point charge Equation

Answer 6

E = Q / 4 pi Ę r^2

Ę= permittivity of free space
R= distance from centre of charge/radius
Q: charge producing field

Question 7

Deflection in electric field depends on: (3)

Answer 7

Mass
Charge
Speed

Question 8

Coulomb equation (force between 2 charges)

Answer 8

F= Q1Q2/ 4 pi Ę r^2

F= electrostatic force between 2 charges

Question 9

Electric potential equation (due to point charge)

Answer 9

V = Q / 4 pi Ę r

(Include minus sign in charge Q)

V=electric potential
(Instead of r^2)

Question 10

Electric potential energy (of 2 point charges) equation

Answer 10

Ep = Q1Q2/ 4 pi Ęr

(No r^2 compared to force)