Electricity and Magnetism Definitions

Question 1

What is Conductor?

Answer 1

Material allowing charge flow (e.g. metals).

Question 2

What is Conducting plate?

Answer 2

Flat conductive surface.

Question 3

What is Conducting sphere?

Answer 3

Spherical shell with uniform surface charge.

Question 4

What is Coulomb?

Answer 4

Unit of charge.

Question 5

What is Electric charge?

Answer 5

Property causing forces in EM fields.

Question 6

What is Electric field?

Answer 6

Region exerting force on charges.

Question 7

What is Electrostatic charge?

Answer 7

Resting charge on insulated body.

Question 8

What is Insulator?

Answer 8

Material blocking charge flow.

Question 9

What is Like charges?

Answer 9

Same polarity (repel).

Question 10

What is Point charge?

Answer 10

Charge at a single point.

Question 11

What is Unlike charges?

Answer 11

Opposite polarity (attract).

Question 12

What is Alternating current?

Answer 12

Charge flow reversing direction periodically.

Question 13

What is Ammeter?

Answer 13

Measures current in series.

Question 14

What is Analogue device?

Answer 14

Reads from a scale.

Question 15

What is Conventional current?

Answer 15

Flow of positive charge direction (positive to negative).

Question 16

What is Digital device?

Answer 16

Displays readings digitally.

Question 17

What is Direct current?

Answer 17

Charge flow in one direction.

Question 18

What is Electric current?

Answer 18

Charge passing a point per unit time.

Question 19

What is Electromotive force (EMF)?

Answer 19

Work done per unit charge by source around circuit.

Question 20

What is Potential difference?

Answer 20

Work done per unit charge across a component.

Question 21

What is Volt?

Answer 21

Unit of EMF and potential difference.

Question 22

What is Voltmeter?

Answer 22

Measures PD across component.

Question 23

What is Work done?

Answer 23

Energy transferred in event/process.

Question 24

What is Cross-sectional area?

Answer 24

Area of 2D cross-section.

Question 25

What is Diode?

Answer 25

Allows current one way; logic gate component.

Question 26

What is Filament lamp?

Answer 26

Metal filament whose resistance increases with temperature.

Question 27

What is Resistance?

Answer 27

Opposition to current; = PD/current.

Question 28

What is Resistor?

Answer 28

Restricts current flow.

Question 29

What is Electrical power?

Answer 29

Rate of electrical energy transfer; = current × PD.

Question 30

What is Kilowatt-hour?

Answer 30

Energy used by 1 kW appliance in 1 h.

Question 31

What is Battery?

Answer 31

Collection of cells providing DC.

Question 32

What is Cell?

Answer 32

Single chemical-to-electrical source.

Question 33

What is Circuit diagram?

Answer 33

Graphical circuit representation.

Question 34

What is Fixed resistor?

Answer 34

Constant resistance component.

Question 35

What is Fuse?

Answer 35

Safety filament that melts on surge.

Question 36

What is Generator?

Answer 36

Converts mechanical to electrical energy.

Question 37

What is Heater?

Answer 37

Converts current to heat.

Question 38

What is Lamp?

Answer 38

Converts current to light.

Question 39

What is LDR (Light Dependent Resistor)?

Answer 39

Resistance decreases with light.

Question 40

What is Magnetising coil?

Answer 40

Generates uniform magnetic field.

Question 41

What is Motor?

Answer 41

Converts electrical to mechanical energy.

Question 42

What is NTC thermistor?

Answer 42

Resistance decreases as temperature increases.

Question 43

What is Potential divider?

Answer 43

Splits voltage using resistors/thermistors/LDRs.

Question 44

What is Relay?

Answer 44

Electromagnetically switched switch.

Question 45

What is Switch?

Answer 45

Opens/closes circuit.

Question 46

What is Transformer?

Answer 46

Changes AC voltage via coil turns.

Question 47

What is Variable resistor?

Answer 47

Adjustable resistance.

Question 48

What is Junction?

Answer 48

Intersection of three or more circuit paths.

Question 49

What is Parallel?

Answer 49

Components on separate branches; independent currents.

Question 50

What is Series?

Answer 50

Components in single loop; same current.

Question 51

What is Earthed casing?

Answer 51

Low-resistance path for excess charge.

Question 52

What is Earth wire?

Answer 52

Protects against voltage surges.

Question 53

What is Live wire?

Answer 53

Carries current to device.

Question 54

What is Neutral wire?

Answer 54

Returns current to source.

Question 55

What is Non-conducting casing?

Answer 55

Insulating material around wires.

Question 56

What is Trip switch?

Answer 56

Cuts supply on surge.

Question 57

What is Electromagnetic induction?

Answer 57

EMF produced by changing magnetic flux.

Question 58

What is Fleming’s right-hand rule?

Answer 58

Direction rule for induced current.

Question 59

What is Induced current?

Answer 59

Current from changing magnetic field.

Question 60

What is Generator effect?

Answer 60

EMF induced by relative motion of conductor and field.

Question 61

What is Slip ring commutator?

Answer 61

Maintains AC contacts on rotating coil.

Question 62

What is Carbon brush?

Answer 62

Contacts commutator to circuit.

Question 63

What is Solenoid?

Answer 63

Coil creating uniform internal field.

Question 64

What is Beam of charged particles?

Answer 64

Localized stream with similar energy/direction.

Question 65

What is Deflection?

Answer 65

Change in direction by magnetic force.

Question 66

What is Electric motor?

Answer 66

Coil in field rotating due to forces.

Question 67

What is Split-ring commutator?

Answer 67

Reverses coil current every half-turn.

Question 68

What is High-voltage transmission?

Answer 68

Power distributed at high voltage.

Question 69

What is Step-down transformer?

Answer 69

Secondary PD < primary PD.

Question 70

What is Step-up transformer?

Answer 70

Secondary PD > primary PD.

Question 71

What is Turns ratio?

Answer 71

Primary turns/secondary turns.

Question 72

What is Voltage ratio?

Answer 72

Primary PD/secondary PD.