Chapter 3

Question 1

Current

Answer 1

Rate of flow of charge

Question 2

Coulomb

Answer 2

Amount of charge that passes in 1 second when the current is 1 amp
Q=It

Question 3

Potential Difference

Answer 3

Energy per unit of charge

V=W/Q

Question 4

Resistance

Answer 4

R=V/I

How difficult it is for current to flow through it

Question 5

Power

Answer 5

P=VI

Rate of transfer of energy

Question 6

Energy

Answer 6

E=VIT

Question 7

Super Conductors

Answer 7

Zero Resistivity——-
Strong Electomagnets
Power Cables

Question 8

EMF

Answer 8

E=I(R+r)

Question 9

Kirchhoff’s First law

Answer 9

Total entering junction=Total Leaving it

Current

Question 10

Kirchhoff’s Second Law

Answer 10

Total emf in series=Sum of PD across each component

Question 11

Series Circuits

Answer 11

RTotal=R1+R2+R3
Same Current at all points
EMF split between components

Question 12

Parallel Circuits

Answer 12

1/RTotal = 1/R1 + 1/R2 + 1/R3
Current split at each junction
Same pd across all components

Question 13

I/V Graphs

Answer 13

Show how resistance varies

Question 14

I/V Characteristic for a metallic conductor

Answer 14

Straight line

Question 15

I/V Characteristic for a Filament Lamp

Answer 15

Straight line

Question 16

Resistance of a Thermistor

Answer 16

Depends on Tempreture

Question 17

Resistance of an LDR

Answer 17

Depends on Light intensity

Question 18

Diodes

Answer 18

Only let current flow in one direction

Question 19

Resistivity

Answer 19

p=RA/L