unit 3 circuits practical exam

Question 1

explain what it means by a positive correlation

Answer 1

when an increase in the independent variable causes an increase in the dependent variable

Question 2

explain what it means by a negative correlation

Answer 2

when an increase in the independent variable causes a decrease in the dependent variable

Question 3

explain what it means by a plateau

Answer 3

when an increase in the independent variable causes no increase or decrease in the dependent variable

Question 4

what does an ammeter do

Answer 4

measures current that flows through a component in a circuit and places in series

Question 5

function of voltmeter

Answer 5

measures voltage across a component in a circuit and placed in parallel

Question 6

function of resistor

Answer 6

controls the current in a circuit

Question 7

function of variable resistor

Answer 7

used to change the current in a circuit and is places in series

Question 8

function of diode

Answer 8

only allows current to flow one way through a circuit and places in series

Question 9

how to calculate total resistance

Answer 9

1/ total resistance

Question 10

how to calculate power

Answer 10

power=voltage times current

Question 11

how to calculate cost of electricity

Answer 11

cost of electricity = power of appliance in kW x time used in hours x cost per kilowatt-hour​

1kWh – 1000 W x 3600s = 3600000J