Chapter 8 Current and Charge

Question 1

What is electric current?

Answer 1

the rate of flow of charged particles

Question 2

what is the unit of current?

Answer 2

Amperes

Question 3

what is the current equations?

Answer 3

Charge / time taken

Question 4

what is the unit of charge?

Answer 4

Coulomb

Question 5

what are the two types of charge?

Answer 5

positive and negative

Question 6

what is the force between two charged particles?

Answer 6

electrostatic forces

Question 7

what is the elementary charge in proton and electron?

Answer 7

(-+) 1.60x10^-19

Question 8

what is the net charge of an object is given by?

Answer 8

Q = (+-) ne

Question 9

what an electric charge in metals?

Answer 9

flow of electron

Question 10

what is conventional current?

Answer 10

current from a positive terminal to a negative one

Question 11

what direction is the flow of electrons?

Answer 11

the opposite direction of conventional current

Question 12

what is used to measure current?

Answer 12

ammeter

Question 13

what is kirchoffs first law?

Answer 13

sum of current entering the junction is = to sum of current exiting the junction

Question 14

what is the conservation of charge?

Answer 14

Charge can neither be created nor destroyed

Question 15

what is kirchoffs first law based of?

Answer 15

the conservation of charge

Question 16

What is number density?

Answer 16

number of free electrons per cubic metre of a material?

Question 17

what is the number density in insulators?

Answer 17

0

Question 18

how do semi conductors carry the same current as conductors?

Answer 18

the electrons move faster

Question 19

What is the electric current equation with mean drift velocity?

Answer 19

I = A n e v
A - cross sectional area
n - number of electrons
e - elementry charge
v - mean drift velocity

Question 20

if cross sectional area decreases what happens to mean drift velocity?

Answer 20

mean drift velocity increases