Topic 6 - Electricity Flashcards Preview

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Flashcards in Topic 6 - Electricity Deck (19)
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1
Q

Charge carriers

A

Charged particles that move through a substance when a pd is applied across it.

2
Q

Circuit rule for current (Kirchhoff’s first law)

A
  1. The current passing through two or more components in series is the same through each component.
  2. At a junction, the total current in = the total current out.
3
Q

Circuit rules for pd (Kirchhoff’s second law)

A
  1. For two or more components in series, the total pd across all the components is equal to the sum of the pds across each component.
  2. The sum of the emfs round a complete loop in a circuit = the sum of the pds round the loop.
4
Q

Critical temperature of a superconducting material.

A

Temperature at and below which it’s resistivity is zero.

5
Q

Electrolyte

A

A solution or molten compound that conducts electricity.

6
Q

Electromotive Force (EMF)

A

The amount of electrical energy per unit charge produced inside a source of electrical energy.

7
Q

Internal resistance

A

Resistance inside a source of electrical energy; the loss of pd per unit charge in the source when current passes through it.

8
Q

Light-dependent resistor

A

Resistor which is designed to have a resistance that changes with light intensity.

9
Q

Negative temperature coefficient

A

The resistance of a semiconductor decreases when its temperature is increased.

10
Q

Ohm’s law

A

The pd across a metallic conductor is proportional to the current, provided the physical conditions do not change.

11
Q

Positive temperature coefficient

A

The resistance of metal increases when its temperature is increased.

12
Q

Potential difference

A

Work done or energy transferred per unit charge between two points when charge is moved from one point to the other.

13
Q

Potential divider

A

Two or more resistors in series connected to a source of pd.

14
Q

Resistance

A

Pd/current

15
Q

Resistivity

A

Resistance per unit length x area of cross-section

16
Q

Semiconductor

A

A substance in which the number of charge carriers increases when the temperature is raised.

17
Q

Superconductor

A

A material that has zero electrical resistance.

18
Q

Terminal pd

A

The potential difference across the terminals of power supply.

19
Q

Thermistor

A

Resistor which is designed to have a resistance that changes with temperature.