# 09. P4 Electric Circuits Flashcards Preview

## SHHS - Science - Physics GCSE 2018on > 09. P4 Electric Circuits > Flashcards

Flashcards in 09. P4 Electric Circuits Deck (37)
1
Q

What charge does an electron have?

A

negative

2
Q

What does a cell do in a circuit?

A

Provides energy to the charge flowing through it.

3
Q

On a cell/battery symbol, which line represents the positive terminal?

A

longer line

4
Q

What does a resistor do in the circuit?

A

It resists the flow of the current through it, energy is transferred into heat energy

5
Q

What is the energy change taking place in a battery/cell?

A

Chemical into electrical and heat

6
Q

What is the direction of conventional current?

A

Travels from positive to negative terminal

7
Q

What direction does the electrons flow in a circuit when connected?

A

Electrons flow from negative terminal to the positive terminal

8
Q

What does a bulb do in the circuit?

A

Converts electrical energy into light and heat energy

9
Q

What does a diode do?

A

It only allows current to flow in one direction

10
Q

What device is used to measure the current in a circuit?

A

Ammeter

11
Q

What is an LDR?

A

Light Dependent Resistor = device whose resistance decreases as more light shines on it

12
Q

What is a thermistor?

A

Device whose resistance decreases as temperature increases

13
Q

What device can be added to a circuit to allow the used to alter the current flowing in a circuit?

A

Variable Resistor

14
Q

What is the purpose of a voltmeter?

A

It is used to measure the potential difference across a device

15
Q

How can thermistors be used in a device?

A

Temperature sensor

16
Q

How can a LDR be used in a device?

A

Light level sensor

17
Q

What happens to the resistance of a thermistor when the temperature increases?

A

Resistance decreases

18
Q

What happens to the resistance of a LDR when the light level increases?

A

Resistance decreases

19
Q

Rule for current measurement in a series circuit?

A

Current is the same at any point in the circuit

20
Q

Rule for current measurement in a parallel circuit?

A

Current leaving the battery splits between each of the branches in the circuit (Battery current = A1 + A2+ A3…)

21
Q

What is electric charge measured in?

A

Coulombs

22
Q

What is the symbol used for electric current?

A

Q

23
Q

What is the symbol used for coulombs?

A

C

24
Q

What are the units of resistance?

A

Ohms

25
Q

State what is meant by resistors obeying Ohm’s law?

A

At a constant temperature, the current through a resistor is directly proportional to the voltage across it

26
Q

Name a component which is said to be an ohmic conductor?

A

Resistor

27
Q

In an I-V graph, a steep line(high gradient) indicates what about the component being tested?

A

28
Q

Explain the curved feature of the IV plot of a filament lamp?

A

As the PD increases, the current increases,causing the temperature to increases so the resistance increases.

29
Q

Why is the diodes IV plot a flat horizontal line along the X-axis in the reverse direction?

A

Because the resistance is very high in reverse direction, as it only allows current to flow in one direction.

30
Q

At what PD across a diode in the forward direction, does the current start to flow?

A

0.6V

31
Q

What happens to the PD of the battery in a series circuit?

A

The PD is shared across each of the components

32
Q

What determines the share of the PD across components in a series circuit?

A

The resistance, a component with a higher resistance compared to the others will have a bigger share.

33
Q

What is the total resistance in a series circuit equal to?

A

For a series circuit, the total resistance is equal to the sum of all the components resistors in the circuit

34
Q

What happens to the PD of the battery in a parallel circuit?

A

The PD over the battery is the same as the PD over each of the branches in the parallel circuit.

35
Q

What happens to the total resistance when you add more resistors in parallel?

A

The total resistance decreases

36
Q

What are the requirements for a static charge to buildup on an object? PHYSICS ONLY

A

Friction between two insulators, electrons transfer from one object to another.

37
Q

Explain in terms of electrons why a polythene rod becomes negatively charged when rubbed with a dry cloth… PHYSICS ONLY

A

Electrons transfer from the surface atoms of the cloth to the rod so the rod becomes negatively charged