Electric Fields

Question 1

Compare the of magnitude of gravitational and electrostatic forces between subatomic particles.

Answer 1

The magnitude of electrostatic forces between subatomic particles is magnitudes greater than the magnitudes of gravitational forces. This is because the masses of subatomic particles are incredibly small compared to their charges.

Question 2

Define electric field strength

Answer 2

The force acting on a positive test charge of unit charge, when it is placed in the field at that point.

Question 3

Derive the equation for work done moving charge between plates

Answer 3

Work done= Fxd
Rearrange E=F/Q to get F= EQ
Rearrange d=ΔV/E
Work done= EQ X ΔV/E= QΔV

Question 4

Describe the trajectory of moving charged particle entering a uniform electric field initially at a right angle

Answer 4

Parabolic shape, as the particle accelerates towards the plate of opposite charge to it

Question 5

Define electric potential

Answer 5

The electric potential at a point, V, is the work done per unit positive charge in bringing a small positive test charge from infinity to that point.

Question 6

What is an equipotential surface?

Answer 6

A surface for which the electric potential is the same along, such that no work is done by a charge when it moves along the surface.

Question 7

When is electric potential positive/negative?

Answer 7

Positive charge= positive
Negative charge= negative