Current-Voltage Characteristics of a bulb In this experiment you are going to investigate how the current through a bulb changes according to the.

Slides:



Advertisements
Similar presentations
IV Characteristics Electricity Lesson 4.
Advertisements

Basic Electronics.
AS Level Electricity - Circuits
EDEXCEL IGCSE / CERTIFICATE IN PHYSICS 2-4 Electrical Resistance
Ohm’s Law Mitsuko J. Osugi Physics 409D Winter 2004 UBC Physics Outreach.
Current. Electrons Flow - + Electrons are negatively charged and therefore flow from negative to positive e-
P2.3.1 – Static Electricity. Objectives, to understand that: –When certain electrical insulators are rubbed together they become electrically charged.
What is electric current? What is current measured in? What is the difference between a series and parallel circuit? How many circuit symbols can you draw?
P5 Electric Circuits OCR 21st Century Georg Simon Ohm
LDRs & Thermistors Noadswood Science, 2012.
P6 Flavour Sharing Charging Logic gates Motoring and Generators Resisting Computer circuits Transformers lessons 8 Home works End of topic assessment.
Teaching note Just in case you have never tried this before. This is split into 6 spaced learning presentations. The idea is that each one is presented.
Circuit Electricity 4 th form IGCSE Textbook: parts of Chapters 7,9 & 10.
Electricity - Basic ideas… Electric current is when electrons start to flow around a circuit. We use an _________ to measure it and it is measured in ____.
Explaining the shape of the current-voltage graph for the bulb
How hot is it? Current – Voltage graphs Dependence of resistance on heat LDRs and thermistors.
Electrical resistance Resistance measures how difficult it is for current to flow.
P2: Electricity Booklet 1 Name: _______________________ Teacher: _______________________ You are reminded for the need to complete all work to the best.
 Electricity is caused by the flow (or net movement) of Electrons  Electric Current – the rate that positive charges flow in a circuit › Actually a.
Circuit Components. Specification Charge, current and potential difference Electric current as the rate of flow of charge; potential difference as work.
RESISTORS Always remember…… V = IR (V= voltage in volts; I = current in amps; R = resistance in ohms)
Electrical Resistance Electrical resistance is a measure of how difficult it is for electricity (electrons) to flow through a material. The units of resistance.
Turn up the heating The electric current Heating effects of a current Voltage – Current graphs.
Electrical Resistance When the same p.d. is applied across different conductors, different currents flow. Some conductors offer more opposition or resistance.
5.3 More current – pd graphs The resistance of a filament lamp increases with increased temperature The resistance of a diode depends on the p.d. (voltage)
Unit 6 in four lessons Resistors.
Look at the picture below What else might effect the resistance of a wire?
Chapter 17 Current and Resistance. Electric Current Whenever electric charges of like signs move, an electric current is said to exist The current is.
Electricity 2 Thomas Edison Lesson Objectives I know some circuit symbols for common components. I know what is meant by resistance I know.
Additional Physics – Forces L/O :- To know how LDR’s are affected by light intensity LDR’s Exam Date -
Chapter 8. Ohm’s Law  George Ohm experimented with circuits and came up with a mathematical relationship relating voltage, current and resistance in.
Circuit Electricity May 30, 2012 Chapter 22. Terms  Current: Flow of charge  Symbolized by “ I ”  Units = Coulombs/second = Amperes (A)  Circuit:
18.3 Resistance and Ohm’s law Resistance of a tungsten filamentExample 5 A student carried out an experiment to find the resistance of the tungsten filament.
PHYSICAL SCIENCE Electricity Part 2: Current Current Objectives Describe how batteries are sources of voltage. Explain how a potential difference.
Simple Electric Circuits. Menu Circuit Symbols Current Voltage Resistance Summary Table.
Electrical Circuits Revision. KEY WORDS: Insulating Electron Attract Repel Resistance Series ASSESSMENT: P2 REVISION – CHAPTER 4 – Current Electricity.
DC Circuits Circuits can be very simple……. Or complex …………
Electrical Circuits j Explain the design and use of circuits to explore variation of resistance – including for lamps, diodes ntc thermistors and.
Current is the rate of flow of….. Energy Charge protons
ELECTRICAL RESISTANCE
ELECTRONICS Learning Objective To know how the thermisistor works
ELECTRONICS Learning Objective To know how the thermisistor works
Electrical Circuits lesson 3
Potential Divider Aims What is a potential divider
EDEXCEL IGCSE PHYSICS 2-4 Electrical Resistance
LDRs and Thermistors.
Series Circuit – 1 bulb Series Circuit – 1 bulb.
Be able to describe how the resistance of LDRs and Thermistors varies.
Series and parallel circuits
Resistance in Circuits
Ohms Law required Practical
Electrical Resistance
AS Level Electricity - Circuits
Circuit Symbols Switch (open): Switch (closed): Battery: Cell:
To verify Joules Law Measure temperature rise for various currents.
Equipment REQUIRED PRACTICAL.. This is a series of 3 practicals with graphs that need to be drawn. This will take multiple lessons Guidance for each practical.
Resistance components & Power
High School Science Current, Voltage and Resistance
P2 REVISION – CHAPTER 2 – Electricity Answers
Circuit Components.
P2 - Physics Circuits.
Voltage Difference The difference in electrical potential between two places. Unit of measure = V (volts) Voltage causes current to flow through an electric.
Describe the action of thermistors and light- dependent resistors and show understanding of their use as input transducers Thermistor A transducer is an.
Resistance.
Presentation transcript:

Current-Voltage Characteristics of a bulb In this experiment you are going to investigate how the current through a bulb changes according to the voltage across it. Current (amp) Voltage (Volt) V 0.00 0.00 A To get negative currents and voltages, use reverse polarity on the battery pack

A graph of the results should look like this Hot filament *resistance increases *current does not increase in proportion to voltage *filament is non- ohmic Current /A BULB Voltage / V Cold filament *constant resistance *current is directly proportional to voltage. *The metal filament inside the bulb follows ohms law

In the forward direction the line curves towards the current axis. (What is happening to the resistance?) Diodes are non- ohmic conductors DIODE 1.2 What is the resistance of the diode when the voltage is 2V? In the reverse direction, current flow is very, very low. Is the resistance of the diode high or low? R = V / I R = 2 V / 1.2 A R = 1.7 Ω

Thermistor A thermistor’s resistance decreases as the temperature rises. USE: temperature sensor, fire alarm

Light dependent resistor (ldr) An LDR’s resistance decreases as the amount of light falling on it increases. USE: street lights

What do the current-voltage graphs look like for a thermistor and an LDR? The line is straight so the resistance is constant for a set temperature. High temperature Current (A) Low temperature But at lower temperatures the resistance is higher (so the current is lower) Voltage (V) The line is straight so the resistance is constant for a set light level. Current (A) Voltage (V) Bright light Dim light LDR But at lower light levels the resistance is higher (so the current is lower)