22 : Electric fields

Question 1

define electric field strength

Answer 1

force experienced per unit positive charge at the point

Question 2

field produced by positive point charge

Answer 2

• a repulsive field
• direction of field away from object
• repels positive charge

Question 3

field produced by negative point charge

Answer 3

• a attractive field
• direction of field towards the object
  attracts positive charge

Question 4

define electric potential

Answer 4

work done per unit charge in bringing positive charge from infinity to that point

Question 5

define electric potential difference

Answer 5

work done per unit charge between two points around the particle of charge

Question 6

effect of distance on electrostatic force

Answer 6

the greater the distance the weaker the force

Question 7

what is coulomb’s law

Answer 7

the force between any two point charges is proportional to the product of their charges and inversly proportional to teh square of the distance between them.

Question 8

permittivity

Answer 8

the ability of a material to transmit an electric field

Question 9

formula for potential at a point in a field

Answer 9

V = W/Q

Question 10

motion of charged particles in a electric field

Answer 10

• projectile motion
• two components of motion are independent
• velocity perpendicular is not affected

Question 11

calculate velocity parallel to plate

Answer 11

• time = length of charged plate / perpendicular speed
• acceleration = Eq/m
  = v = u+at

Question 12

formula for electric potential energy near a point charge

Answer 12

E = vq