circuits

Question 1

current

Answer 1

charge / time

Question 2

potential difference

Answer 2

work done / charge

Question 3

power

Answer 3

potential difference * current

Question 4

potential difference

Answer 4

current * resistance

Question 5

series rules

Answer 5

p.d is split, current is same, total resistance = R1 + R2….+Rn

Question 6

parallel rules

Answer 6

p.d is same, current is split, total resistance = (1/R1 + 1/R2…+1/Rn)^-1

Question 7

internal resistance

Answer 7

resistance encountered within the power supply

Question 8

electromotive force (emf)

Answer 8

the energy per unit charge supplied by a cell

Question 9

emf =

Answer 9

p.d. across internal resistance + local resistance

current * (internal resistance + local resistance)

Question 10

low internal resistance

Answer 10

used for rechargeable batteries (phone/laptop) have a low internal resistance allowing them to be recharge using higher current without overheating

Question 11

high internal resistance

Answer 11

high voltage power supplies used in classrooms have a very high internal resistance as a safety feature

Question 12

potential dividers

Answer 12

used when devices need to vary their p.d. when connected to a fixed emf

Question 13

potential divider circuits

Answer 13

able to divide p.d. such that the device is different to the emf of the power supply

Question 14

Vn =

Answer 14

(Rn/total R) * Vin

Question 15

Vout =

Answer 15

(Rn/total R) * Vin