9.1 + 9.2 circuit symbols, p.d , e.m.f

Question 1

draw the symbols for the following:
* cell
* battery
* lamp
* resistor
* variable resistor
* thermistor
* LDR
* diode
* LED (light emitting diode)
* ammeter
* voltmeter

Answer 1

Question 2

what is the nragtive and positive side of the terminal?

Answer 2

positive: long
negative: short

Question 3

what is potnetial difference defined as?

Answer 3

the change in potential energy per unit chrage between two points, due to charge doing work on the circuit components, causing electrical potential energy to decrease

work done per charge carrier

Question 4

what is the equation for potential difference?

Answer 4

V = W/Q
* V= potential difference
* W= difference between electrical energy
* Q= per unit charge

Question 5

what is the difference of 1 volt?

Answer 5

the potential difference between two points when a charge of 1 coulumb passing through the two points experiences a change in electric potential energy (1J)

Question 6

what do voltmeters measure?

Answer 6

the difference in electric potenteial energy per harge

Question 7

how are voltmeters positioned, why do they have high resistance?

Answer 7

in paralle
* they have high resistance to make sure that the component is not short circuited

Question 8

define the electro motive force

Answer 8

• measures the work done to charge carriers when they gain energy at the power supply
• energy transfered from chemical–> electrical
  ε = W/Q where ε = electromotive force (in Volts), W = work done (in Joules) and Q = charge (in Coulombs)

the output

Question 9

what is the difference between the emf and p.d?

Answer 9

• emf: charges gain energy
• pd: charges loose energy
• emf: chemical energy turns electrical
• pd: electrical energy to heat/ other forms
• emf and p.d work done by charges (Volts)