electronics

Question 1

current

Answer 1

rate of flow of charge

Question 2

p.d.

Answer 2

energy change per coulomb of charge

Question 3

resistance

Answer 3

opposition to the flow of current

Question 4

ohms law

Answer 4

voltage is directly proportional to current

Question 5

potential divider

Answer 5

series circuit where each resistor receives a share of the supply voltage

Question 6

Wheatstone bridge

Answer 6

two potential dividers connected in parallel with voltmeter in the middle. the potential difference across the voltmeter can be calculated by calculating the voltage across each resistor and potential difference in the potential divider then calculating the difference between the two

Question 7

power

Answer 7

the electrical energy transferred each second

Question 8

DC

Answer 8

Current flows in one direction at all times

Question 9

AC

Answer 9

current changes direction and instantaneous value with time

Question 10

mains voltage

Answer 10

230V

Question 11

r.m.s value

Answer 11

root mean square value, the average or declared value of a supply

Question 12

peak voltage/current

Answer 12

maximum voltage/current in an AC supply

Question 13

y-gain

Answer 13

a setting on a oscilloscope with controls the voltage per centimetre or division

Question 14

time base

Answer 14

time per centimetre or division

Question 15

period

Answer 15

the time it takes a wave to pass a point

Question 16

frequency

Answer 16

number of waves per second

Question 17

electromotive force

Answer 17

number of joules of energy available to a coulomb of charge passing through the cell

Question 18

internal resistance

Answer 18

opposition the the flow of charges through circuits were supply or source

Question 19

external resistance

Answer 19

opposition to the flow of charges externally to the source

Question 20

terminal potential difference

Answer 20

p.d that can be measured at the terminals of a source = E-Vlost

Question 21

lost volts

Answer 21

difference between EMF and Vtpd pd required for current to pass through the source

Question 22

open circuit

Answer 22

when load resistance is infinite, so no current flows

Question 23

short circuit

Answer 23

when load resistance is 0 results in very high currents

Question 24

capacitance

Answer 24

ability of device to store electrical charge. Ratio of charge stored to pd between two conductors

Question 25

parallel plate capacitor

Answer 25

2 parallel plates connected to power supply both conductors, separated by a distance

Question 26

work done charging capacitor

Answer 26

negatively charged plate stores electrons and work is done each time a new. electron is placed on the plate