(H) Electrical Circuits

Question 1

What are cells, batteries and power packs?

Answer 1

A cell is a component that gives voltage to a circuit.
A battery is made up of more than one cell

Question 2

What is an ammeter and where is it placed in the component?

Answer 2

A component that measures the current

It is placed in series with the circuit

Question 3

What is a voltmeter and where is it placed in the component?

Answer 3

A component that measures the voltage

It is placed in parallel with the circuit

Question 4

What is a lamp/bulb and where is it placed in the component?

Answer 4

A component that causes light when a voltage pass through it

It is placed in series with the circuit

Question 5

What is a (fixed) resistor?

Answer 5

A component that gives a fixed resistance to the current in a circuit

Question 6

What is a variable resistor and where is it placed in the component?

Answer 6

A component that gives a changeable resistance to the current in a circuit

It is placed in series with the circuit

Question 7

What is a thermistor?

Answer 7

A component that gives a resistance that changes depending on the temperature to the current in a circuit

Question 8

What level of resistance would a thermistor have?

Answer 8

If temperature increases - resistance decreases

If temperature decreases - resistance increases

Question 9

What is an LDR?

Answer 9

An LDR is a light dependent resistor which is a component that gives a resistance that depends on the light intensity that falls onto it to the current in a circuit

Question 10

What level of resistance would a LDR have?

Answer 10

If light intensity increases - resistance decreases

If light intensity decreases - resistance increases

Question 11

What is a diode and where is it placed in the component?

Answer 11

A diode is a component that only lets current flow in one direction

It is placed in series in a circuit

Question 12

What is a photodiode?

Answer 12

A component that converts light energy into electrical energy

Question 13

What are LEDs?

Answer 13

Light emitting diodes are components that emits light when currents flow through it

Question 14

What is the word equation for energy?

Answer 14

energy = voltage x current x time

Question 15

What is the symbol equation for energy?

Answer 15

E = V x I x t

Question 16

What is the word equation for physical power?

Answer 16

power = work done/time

Question 17

What is the symbol equation for physical power?

Answer 17

P = E/t

Question 18

What is the word equation for voltage?

Answer 18

voltage = current x resistance

Question 19

What is the symbol equation for voltage?

Answer 19

V = I x R

Question 20

What is the word equation for electrical power?

Answer 20

power = voltage x current

Question 21

What is the symbol equation for electrical power?

Answer 21

P = I x V

Question 22

How are different domestic appliances used to calculate energy usage

Answer 22

Different domestic appliances use different amount of energy and the electrical power equation is used to calculate it

Question 23

What is a fuse?

Answer 23

A component that will blow if there is a fault in the circuit such as there being too much current

Question 24

What does the size of a fuse have to do with current?

Answer 24

Fuse are rated different currents such as 3A or 13A and they are used if a fault in an circuit causes too much current to flow. This protects the rest of the circuit

Question 25

What is the word equation of energy transferred?

Answer 25

energy transferred = power in kilowatts x times in hours

Question 26

What is the symbol equation of energy transferred?

Answer 26

kWh = kW x h