Topic 2 - Circuits

Question 1

what is current?

Answer 1

rate of flow of charge around the circuit

Question 2

what carries charge in a circuit?

Answer 2

electrons

Question 3

why would a current not flow through a component?

Answer 3

current will only flow through a component if there is voltage across that component

Question 4

what is the unit for current?

Answer 4

ampere (amp), A

Question 5

what is voltage?

Answer 5

what drives the current around the circuit

Question 6

what can voltage also be called?

Answer 6

potential difference

Question 7

what is the unit for voltage?

Answer 7

volt, V

Question 8

what is resistance?

Answer 8

anything in the circuit which slows the flow down

Question 9

what happens to resistance if you add more components?

Answer 9

resistance becomes higher overall

Question 10

what is the unit for resistance?

Answer 10

ohm, Ω

Question 11

what decides how large the current is?

Answer 11

voltage and resistance

Question 12

what does an ammeter measure?

Answer 12

current

Question 13

where do you place an ammeter?

Answer 13

in series anywhere in the main circuit

Question 14

what does a voltmeter measure?

Answer 14

voltage

Question 15

where do you place a voltmeter?

Answer 15

in parallel around the component under test (the component you’re measuring)

Question 16

what happens if you vary a variable resistor?

Answer 16

it varies the current flowing through the circuit

Question 17

what type of current is mains electricity?

Answer 17

a.c supply

Question 18

what is an a.c supply?

Answer 18

the current is constantly changing direction

Question 19

what type of current is a cell/battery?

Answer 19

d.c. supply

Question 20

what is d.c supply?

Answer 20

the current keeps flowing in the same direction