Electric Fields

Question 1

What does the direction of the field show?

Answer 1

the direction of force experienced by a small positive charge placed at a point

Question 2

What is indicated by the separation between the field lines?

Answer 2

electric field strength

Question 3

What is a uniform field made up of?

Answer 3

2 oppositely charged parallel plates

Question 4

What are electric field lines always perpendicular to?

Answer 4

the surface of the conductor

Question 5

What are radial field lines like?

Answer 5

straight field lines converging to a point at the centre of the charged object

Question 6

What happens to field strength as the distance from the object increases?

Answer 6

gets smaller

Question 7

How do you calculate electric field strength?

Answer 7

(force experienced by positive charge)/(positive charge)

Question 8

What is Coulombs law?

Answer 8

two point charges exert an electrostatic force on each other that is directly proportional to the product of their charges and inversely proportional to the square of the distance between them

Question 9

What happens to electric field strength and radius within radial fields?

Answer 9

E obeys the inverse square law with r

Question 10

What are the similarities between gravitational and electric fields?

Answer 10

• field strengths both obey inverse square law with distance
• both produce a radial field pattern

Question 11

What are the differences between gravitational and electric fields?

Answer 11

• gravitational depends on mass but electric on charge

- gravitational always produce attractive but electric can be attractive or repulsive

Question 12

What direction of force will a particle of positive charge Q+ experience in a uniform electric field?

Answer 12

in the direction of the field

Question 13

What happens to a particle of positive charge Q+ in. uniform electric field?

Answer 13

particle moves from positive to negative

Question 14

How do you calculate the work done of a positively charged particle in a uniform electric field?

Answer 14

VQ

Question 15

When does a particle accelerate in a uniform electric field?

Answer 15

when a positive charge moves in the direction of the field

Question 16

When does a particle decelerate in a uniform electric field?

Answer 16

when a negative charge moves in the direction of the field

Question 17

What happens when the motion of a particle is perpendicular to the field in a uniform electric field?

Answer 17

parabolic path when initial velocity is perpendicular to the direction of the field

Question 18

What remains constant when the motion of a particle is perpendicular to the field in a uniform electric field?

Answer 18

velocity

Question 19

What must be done to bring like charged particles together?

Answer 19

external work

Question 20

What is the area under a force separation graph equal to?

Answer 20

work done on the charged particles

Question 21

Define electric potential enegry:

Answer 21

work done on the charged particles from infinity to separation r

Question 22

When and why is electric field strength negative sometimes?

Answer 22

2 particles with unlike charges as external work must be done

Question 23

When does electric potential energy equal 0?

Answer 23

at infinity