Physics-electrcity

Question 1

What is the basic concept of electricity?

Answer 1

Static electricity is electric charges basically gong nowhere. Electric current is a net flow of electric charge.

Question 2

What is the units of electric charge?

Answer 2

Electric charge is in coulomb, C

Question 3

What is electric current measured in?

Answer 3

Measured in Coulombs per second, aka Amperes

Question 4

What is the electric current equation?

Answer 4

i=q/t
Where 
i is the current in Amperes
Q is the total amount of charge (in coulombs)
t is time in seconds

Question 5

Conductors vs Insulators:

Answer 5

In a conductor, electric current can flow freely, in insulators it cannot.

Question 6

Write the variations of the electric current equation:

Answer 6

i=q/t.
t=q/i
q=it

Question 7

Write how to change milli, micro and nano:

Answer 7

Milli= x10^-3
Micro= x10^-6
nano= x10^-9

Question 8

Why do electrons come out of the negative terminal?

Answer 8

Electrons have a negative charge and therefore are attracted to the positive terminal.

Question 9

Write Ohm’s law:

Answer 9

V=IR

Question 10

Explain resistance:

Answer 10

Resistance is a property of a component that describes its tendency to oppose the flow of electric current. Good conductors have very low resistance.

Question 11

Explain voltage:

Answer 11

Potential difference is measured from on point in the circuit to another point. Voltage does NOT go through things.

Question 12

Explain Current:

Answer 12

Current is measured at a point. Current DOES flow through things.

Question 13

Write the variations of ohms law:

Answer 13

i=V/R

R=V/I

Question 14

What is the two ways resistors can be combined?

Answer 14

Circuit elements can be connected in two ways:
SERIES (one after the other)
PARALLEL (met at the same time by the current)

Question 15

Fact about series:

Answer 15

Connecting resistors in series always increases the total resistance.

Question 16

Fact about parallel:

Answer 16

Connecting resistors in parallel always decreases the total resistance.

Question 17

Series resistance formula:

Answer 17

Req=R1+R2+R3…..

Question 18

Parallel resistance formula:

Answer 18

1/Req=1/R1+1/R2+1/R3….

Question 19

Warning for parallel resistors:

Answer 19

The formula for resistors in parallel does not give the answer, but rather the recipricol of the answer.

Question 20

Basic formula for electric power:

Answer 20

P=V.i

Question 21

Rewrite the electric power formula using ohm’s law:

Answer 21

P=V.i
P=i^2.R
P=V^2/R

Question 22

Write the formula for the rate of doing work (power):

Answer 22

P=w/t
where P=power (in watts or joules/second)
w=work (in joules)
t is time (in seconds)

Question 23

Formula for energy:

Answer 23

Energy=powere x time

Question 24

Insulators:

Answer 24

Most solid materials are classified as insulators because they offer very large resistance to their flow of electric current.

Question 25

Conductors:

Answer 25

Metals are classified as conductors because their outer electrons are not tightly bound.