ch22 - coulomb's law

Question 1

electric field, symbol E

Answer 1

. field of force
. represted by field lines

Question 2

electric field strength at a point

Answer 2

E = F/Q

Question 3

uniform field between charged parallel plates

Answer 3

E = V/d

Question 4

Coulomb’s law

Answer 4

any two point charges exert an electrical force on each other that is proportional to the product of their charges and inversely proportional to the distance between them squared

Question 5

F = q1q2 / 4piepsilon 0 * r²

Answer 5

coulomb’s law

Question 6

permittivity of free space

Answer 6

an electrical constant usually denoted by the epsilon0 with value = 8.85*10^12 Fm-1

Question 7

E = Q/4* pi * epsilon0 * r²

Question 8

if work is done in moving charge across parallel charged plates

Answer 8

potential energy is increasing

Question 9

potential energy

Answer 9

energy change per unit charge

Question 10

V = W/Q

Question 11

electric potential

Answer 11

the electric potential at a point is equal to the work done per unit charge in bringing unit positive charge form infinity to that point

scalar

Question 12

V = Q/ 4 *pi * epsilon0 * r

Answer 12

electric potential in a radial field due to a point charge

Question 13

potential energy of a pair of point charges

Answer 13

Ep = Qq/4 * pi * epsilon0 * r

Question 14

potential difference between two from a charge

Answer 14

<>V = (Q/4pi epsilon0) *
[1/r1 - 1/r2]

Question 15

electric field strength

Answer 15

• potential gradient

Question 16

E = - <>V / <>d

Question 17

difference between gravitational and electrical fields: origin

Answer 17

GRAVITATIONAL FIELDS
. arise from masses

ELECTRIC FIELDS
. arise from electric charges

Question 18

difference between gravitational and electrical fields: vector force

Answer 18

GRAVITATIONAL FIELDS
. only attraction

ELECTRIC FIELDS
. both attraction and repulsion

Question 19

difference between gravitational and electrical fields: formula

Answer 19

GRAVITATIONAL FIELDS
. g = F/m

ELECTRIC FIELDS
. E = F/Q

Question 20

difference between gravitational and electrical fields: units

Answer 20

GRAVITATIONAL FIELDS
. N kg-1 or ms-2

ELECTRIC FIELDS
. NC-1 or Vm-1

Question 21

difference between gravitational and electrical fields: uniform fields

Answer 21

GRAVITATIONAL FIELDS
. parallel gravitational field lines
. g = constant

ELECTRIC FIELDS
. parallel electric field lines
. E = v/d

Question 22

difference between gravitational and electrical fields: spherical fields

Answer 22

GRAVITATIONAL FIELDS
. F = GMm/r²
. g = GM/r²

ELECTRIC FIELDS
. F = Q1Q2 / 4piepsilon0 * r²
. E = Q/ 4piepsilon0 * r²

Question 23

difference between gravitational and electrical fields: potential

Answer 23

GRAVITATIONAL FIELDS
. potential = GM/r
. 0 at infinty
. scalar
. always negative

ELECTRIC FIELDS
. V = Q/ 4piepsilon0 * r²
. 0 at infinity
. scalar
. both positive and negative