Course Content
Properties of Matter
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Explain the three states of matter. 2.Explain phenomenon of surface tension. 3.Explain gas laws.
0/3
Introduction
States Of Matter
Gas Laws
Measurement
OBJECTIVES By the end of this topic , the trainee should be able to: 1.State the basic and derived quantities of measurements 2.Describe quantities of measurements 3.State the SI units of quantities of measurements and their sub-multipliers 4.Convert units from one to another
0/4
Introduction
Measurement of Length and Distance
  Measurement of Mass and weight
 Measurement of Volume and Density
Pressure
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Define pressure 2.Determine pressure in solids and fluids 3.Explain the type of instruments used in measurement of pressure of gases 4.Explain transmission of presure in liquids
0/2
Introduction
Measuring Pressure
Force
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define force and its SI units 2.Explain types of force 3.Measure force 4.Work out calculations involving force 5.Explain Hooke’s law
0/3
Force
Friction Force
Centrifugal and Centripetal Force
Hooke’s Law
Hooke's Law  is a law named after 17th century British physicist Robert Hooke, who sought to demonstrate the relationship between the forces applied to a spring and its elasticity.
0/1
Hooke’s Law
Moments
OBJECTIVES By the end of this topic, the trainee should be able to: 1. Define moments of a force 2.Explain principles of moments 3.Explain statics , dynamics and kinematics
0/1
Moments
Velocity and Speed
OBJECTIVES By the end of this topic , the trainee should be able to : 1.Define speed and velocity 2.Explain types of motion 3.Determine Linear Determine Circular Motion
0/1
Velocity and Speed
Work and Power
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Define work and power 2.Work out calculations involving work and power
0/1
Work and Power
Energy
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define energy 2.Explain forms of energy 3.Explain law of conservation of energy
0/1
Energy
Motion
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define motion 2.Explain causes of motion 3.Explain types of motion 4.Describe linear and circular motion
0/3
Introduction
Linear Motion 
Circular Motion
Newton’s Laws of Motion
OBJECTIVES By the end of this topic, the trainee should be able to: 1.State Newton’s laws of motion 2.Explain relationships between mass and inertia 3.Explain significance of Newton’s laws of motion
0/1
Newton’s Laws of Motion
Heat and Heat Transfer
OBJECTIVES By the end of this topic, the trainee should be able to 1.Define temperature and heat 2.Describe instruments used to measure temperature 3.Explain modes of heat transfer 4.Explain factors that influence heat transfer 5.Explain heat capacity, specific heat capacity and specific latent heat of substances 6. Work out calorimetric calculations
0/5
Introduction
Instruments Used For Measuring Temperature  
Heat Transfer
Measuring The Quantity Of Heat
Heat and Changes of State
Light
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Define light and its properties 2.Explain types of mirrors and lenses 3.Explain reflection and refraction of light 4. Explain the lens formulae
0/10
Introduction
Mirrors
Reflection 
Mirror Equation
Image Formation By Convex Mirror
Refraction Of Light
 Refractive index
Thin Lenses
The lens formula
 Uses of lenses on optical devices
WAVES
OBJECTIVES By the end of this topic , the trainee should be able to : 1. Define waves 2.Explain types of waves 3.Explain characteristics and properties of waves 4.Explain rectilinear propagation of waves 5.Describe refraction of waves 6.Describe sound and sound waves
0/6
Introduction
Electromagnetic Wave
Electromagnetic Wave
Properties of Waves
Rectilinear Propagation Of Waves
Sound and Sound Waves
Electrostatics
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Define electrostatics 2. Describe the working of electroscopes 3.Describe different methods of charging a body 4.Explain electric fields 5.Describe charge distribution on conductors’ surface 6. Describe capacitors and capacitance
0/5
Introduction
Gold Leaf Electroscope
Electric Fields
Charge Distribution on Conductors’ Surface
Capacitors And Capacitance
Magnetism and Electromagnetism
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define magnetism 2.Identify magnetic and non- magnetic materials 3.Explain properties of magnets 4.Describe magnetic field patterns 5.Describe making magnets 6.Explain domain theory of magnets 7.Describe magnetic effect of an electric current. 8. Describe electromagnets and electromagnetism 9.Describe electromagnetic induction
0/6
Introduction
Magnetic Field Patterns.
Making Magnets
Magnetic Effect of An Electric Current.
Electromagnetism 
Electromagnetic Induction
Current Electricity
CURRENT ELECTRICITY OBJECTIVES By the end of this topic, the trainer should be able to: 1. Define current and electricity 2.Electric potential difference 3.Explain use of a meters, voltmeters and resistors 4.Explain ohm’s law 5. Explain Electromotive force and internal resistance 6.Describe production of electric current 7.Describe simple cells, Leclanche’ cell, dry cells and lea-acid accumulators 8.Describe mains electricity 9.Describe domestic wiring
0/6
Introduction
Electric Potential Difference And Electric Current
Resistors and Resistance
Production Of Electric Current:
Heating Effect Of An Electric Current
Mains Electricity
Electromagnetic Spectrum
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Define magnetic spectrum 2. Explain properties of electromagnetic waves 3. Describe applications of electromagnetic radiation
0/2
Introduction
Properties and Application of Electromagnetic Waves
Radioactivity
OBJECTIVES By the end of this topic, the trainee should be able to: 1. Define radioactivity 2.Classify radiations 3.Explain the properties of radiation materials 4.Describe nuclear fission and nuclear fusion 5.Describe methods for detecting nuclear radiation 6.Describe activity and half-life of elements 7. Discuss hazards of radioactivity and their precautions 8. Outline the applications of radioactivity
0/4
Introduction
Nuclear Fission
Activity and Half-Life Of Elements
Applications Of Radioactivity
Cathode and X-Rays
OBJECTIVES By the end of this topic, the trainee should be able to: 1. Define cathode and X- rays 2.Explain production of cathode and X- ray 3.Explain properties of cathode and X- ray 4.Describe cathode ray oscilloscope (CRO) 5. Describe the applications of Cathode and X-rays
0/2
Cathode Rays
X-Rays
Physics Techniques For Science Laboratory Technicians
About Lesson

Views: 30

 Thin Lenses

A lens is conventionally defined as a piece of glass which is used to focus or change the direction of a beam of light passing through it.

 They are mainly made of glass or plastic. Lens are used in making spectacles, cameras, cinema projectors, microscopes and telescopes.

Types of thin lenses.

A lens which is thicker at its centre than at its edges converges light and is called convex or converging lens.

 A lens which is thicker at its edges than at its centre diverges light and is known as concave or diverging lens.

· Properties of lenses.

  1. Optical centre – this is the geometric centre of a lens which is usually shown using a black dot in ray diagrams. A ray travelling through the optical centre passes through in a straight line.
  2. Centre of curvature – this is the geometric centre of the circle of which the lens surface is part of. Since lenses have two surfaces there are two centres of curvature. C is used to denote one centre while the other is denoted by C1.
  3. Principal axis – this is an imaginary line which passes through the optical centre at right angle to the lens.
  4. Principal focus – this is a point through which all rays travelling parallel to the principal axis pass after refraction through the lens.

 A lens has a principal focus on both its sides. F is used to denote the principal focus

  1. Focal length – this is the distance between the optical centre and the principal focus. It is denoted by ‘f’.
  • ·

 The principal focus for a converging lens is real and virtual for a diverging lens.

It is important to note that the principal focus is not always halfway between the optical centre and the centre of curvature as it is in mirrors.

  • ·

Images formed by thin lenses.

The nature, size and position of the image formed by a particular lens depends on the position of the object in relation to the lens.

 Construction of ray diagrams

  Three rays are of particular importance in the construction of ray diagrams.

  1. A ray of light travelling parallel to the principal axis passes through the principal focus on refraction through the lens. In case of a concave lens the ray is diverged in a way that it appears to come from the principal focus.
  2. A ray of light travelling through the optical centre goes un-deviated along the same path.
  3. A ray of light travelling through the principal focus is refracted parallel to the principal axis on passing through the lens.

 The construction of the rays is illustrated below.

  • ·

 Images formed by a converging lens.

  1. Object between the lens and the principal focus.
  • ·

 – Image formed behind the object

– Virtual

– Erect

– Magnified

  1. Object at infinity.
  • ·

– Image formed at the principal focus of the lens

– Real

 – Inverted

 – Diminished

  1. Object at the principal focus (at F).
  • ·

  – Image is at infinity.

  1. Object between the principal focus (F) and 2 F.
  • ·

  – Image situated beyond 2 F

– Real

 – Inverted

– Magnified

  • 5. Object at 2 F.
  • ·

  – Image is formed at 2 F

– Real

  – Inverted

– Same size as the object

  • 6. Object beyond F.
  • ·

 – Image moves nearer to F as object shifts further beyond 2 F

– Real

 – Inverted

 – Diminished

 Images formed by a diverging lens.

 Images formed by diverging lens are always erect, virtual and diminished for all positions of the object.

  • ·

Linear magnification.

The linear magnification produced by a lens defined as the ratio of the height of the image to the height of the object, denoted by letter ‘m’, therefore;

  m = height of the image / height of the object.

 Magnification is also given by = distance of the image from the lens/ dist. of object from lens. m = v / u

 Example

 An object 0.05 m high is placed 0.15 m in front of a convex lens of focal length 0.1 m.

 Find by construction, the position, nature and size of the image. What is the magnification?·


Join the conversation
Previous
Next

You cannot copy content of this page