Electricity Definitions

Question 1

K’s 1st law

Answer 1

Due to conservation of charge.
Total current entering junction is equal to total current leaving it

Question 2

Mean drift velocity

Answer 2

Average velocity of electron passing through object

(Proportional to current, Inversely proportional to charge carriers and area)

Question 3

EMF

Answer 3

• Energy per unit charge supplied by a source
• Energy transferred to charge carriers

• Energy transformed to electrical
• Charges gain energy
• Work done on charges

Question 4

Pd

Answer 4

• Energy transferred by the charge carriers as they move through the component
• Energy transformed from electrical
• Charges loses energy
• Work done by charges

Question 5

Resistance and resistivity

Answer 5

Resistance- measure of how difficult it is for current to flow

Resistivity- measure of how difficult it is for charge to flow

Question 6

K’s 2nd law

Answer 6

Due to conservation of energy. Sum of pd in closed loop equal to sum of emf

Question 7

Lost volts

Answer 7

Difference between emf and terminal voltage
Equal to pd across internal resistance

Question 8

Terminal voltage

Answer 8

Pd across terminal.
Equal to emf- lost volts

Question 9

Thermistor

Answer 9

• As temp increases, resistance decreases

Question 10

LDR

Answer 10

• as light intensity increases, resistance decreases