# P2 - Current Electricity Flashcards

0
Q

What is transferred when objects become charged?

A

Electrons.

1
Q

What happens when two insulating materials are rubbed together?

A

Some materials become charged.

2
Q

What happens when the charges are brought together?

A

Like charges repel; unlike charges attract.

3
Q

What is a charged atom known as?

A

An ion

4
Q

What affect does removing an electron from an atom have?

A

The atom becomes positively charged.

5
Q

What is the purpose of a circuit diagram?

A

It shows how components are connected.

6
Q

What is the difference between a battery and a cell?

A

A battery consists of two or more cells.

7
Q

What determines the size of an electric current?

A

The rate of flow of charge.

8
Q

How is electric current calculated?

A

Electric current = charge flow / time taken I = Q / t

9
Q

What is potential difference?

A

Pd = energy transferred / charge V = W / Q

10
Q

How is an ammeter connected to a circuit?

A

In series with the component giving the current through it.

11
Q

How is a voltmeter connected to a circuit!

A

Parallel to the component giving the pd across it.

12
Q

How is resistance calculated?

A

Resistance (ohms) = pd (volts) / current (amps)

13
Q

What is the symbol for Ohms?

A

Ω

14
Q

What is an ohmic conductor?

A

A component with a constant resistance.

15
Q

What happens to the resistance of a filament bulb as the temperature increases?

A

The resistance increases with the temeprature. ∴ non-ohmic

17
Q

How does the current through a diode depend on the pd across it?

A

For forward voltage, the resistance is low. For reverse voltage, the resistance is high. ∴ non-ohmic

18
Q

How does the resistance of a thermistor change with temperature.

A

Resistance decreases when the temperature increases.

19
Q

How does the current vary through a series circuit?

A

The same current passes through components in series.

20
Q

How does the pd vary through a series circuit?

A

The total pd of the voltage supply in a series circuit is shared between components.

21
Q

What happens to the pd when more than one cell is used in series?

A

The total pd is the sum of the pd of each cell.

22
Q

How is the total resistance of a series circuit calculated?

A

Adding the resistance of each component.

23
Q

How is the total current calculated in a parallel circuit?

A

The total current is the sum of the currents though the separate components.

24
Q

What is the pd across the components in a parallel circuit?

A

The pd is the same across each component.

25
Q

How is current through a resistor calculated?

A

current = pd / resistance

26
Q

What is the relationship between resistance and current in a parallel circuit?

A

The bigger the resistance, the smaller the current.

27
Q

What is the symbol for a cell on a circuit diagram?

A
28
Q

What is the symbol for a resistor on a circuit diagram?

A
29
Q

What is the symbol for a switch on a circuit diagram?

A
30
Q

What is the symbol for a variable resistor on a circuit diagram?

A
31
Q

What is the symbol for a bulb on a circuit diagram?

A
32
Q

What is the symbol for a fuse on a circuit diagram?

A
33
Q

What is the symbol for a diode on a circuit diagram?

A
34
Q

What is the symbol for a heater on a circuit diagram?

A
35
Q

What is the symbol for an LED on a circuit diagram?

A
36
Q

What is the symbol for a voltmeter on a circuit diagram?

A
37
Q

What is the symbol for an ammeter on a circuit diagram?

A