unit 4: electricity

Question 1

charge:

Answer 1

a property of matter that causes it to experience force when placed in an electromagnetic field

Question 2

current

Answer 2

charge carriers / rate of flow of charge in a circuit

Question 3

ldr:

Answer 3

a light sensitive semiconductor whose resistance increases when light intensity decreases

Question 4

ohmic conductor:

Answer 4

a conductor following ohms law where current flowing through it is directly proportional to the pd between each end of the conductor. conductor is kept a t constant temperature.

Question 5

when voltage increases?

Answer 5

temp increases

Question 6

pd:

Answer 6

the difference in electrical potential between two points in a circuit. work done per coulomb to move a charge from the lower potential point to the higher potential point. measured in volts

Question 7

power:

Answer 7

rate of energy transfer in a circuit. product of current and pd between 2 points. measured in watts.

Question 8

resistance:

Answer 8

opposes current. measure of how difficult it is for current to flow through a material.

Question 9

resistivity:

Answer 9

measure of how difficult it is for a charge to travel through a material. proportional to objects resistance and cross sectional area, and inversely proportional to object length. measured in ohm metres

Question 10

quantisation of charge:

Answer 10

idea that charge can only exist in discrete packets of multiples of the elementary charge

Question 11

thermistor

Answer 11

a temperature sensitive semiconductor whose resistance increases when temperature decreases

Question 12

volt:

Answer 12

unit of pd