WEEK 10
Posted: Wed Jun 24, 2015 12:21 am
TOPIC : FIELD – CONCEPT AND TYPES OF FIELD. GRAVITATIONAL AND MAGNETIC FIELD. FORCE OF GRAVITY
CONTENT:
Concept of Field
Types of Field
Gravitational Field
Concept of Field
Field can be defined as the region or space under the influence of some physical agency such as gravitational, electricity and magnetism.
Types of Field
Fields are of various types namely: gravitational, magnetic and electric field.
Gravitational Field
Gravitational field is any region or space around a mass in which the gravitational force of the mass is felt.
Newton’s law of gravitational states that the force of attraction between two bodies of mass M and m is inversely proportional to the square of their distance R, between their centers and it is directly proportional to the product of their mass.
Mathematical expression:
https://youtu.be/5N_BkadurZA
EVALUATION
1. Define field
2. State Newton law of gravitation
Gravitational Potential
Work is done when mass are moved from one point in a gravitational field to a higher point. Consider a mass (m), raised to a vertical height h from the surface of the earth. The gravitational potential energy = mgh.
Gravitational potential V is stated as the product of universal gravitational constant (G) and the mass (M) to the distance (R) apart.
Mathematically expressed
V = GM/R
https://youtu.be/kFseruQ8YMo
EVALUATION
1. Define gravitational potential
2. Define gravitational field
Reading Assignment : New School Physics pg 67 - 70
ASSIGNMENT(THEORY)
1. Define (a) gravitational field (b) acceleration due to gravity. How does acceleration vary with latitude
2. (a) Explain what is meant by a field as used in physics. (b) Mention three types of field known to you
TOPIC : Electric Field – Line of Forces, Properties of Line of Force, Description and Properties of Force Field
CONTENT
Electric Field
Line of Force and properties
Electric Field
It is simply the space or region around an electric charge where a force is experienced. There are two types of charges namely : positive and negative charges.
Properties of Line of Force.
1. They are imaginary
2. They do not cross each other
3. They begin with a positive charge and end with a negative charge.
4. Electric flux representing uniform field are straight parallels and uniformly space.
5. While the one representing in non uniform field are curves
Coloumb’s Law states that the force experience by two charges Q1Q2 separated by a distance r is directly proportional to their product of their charges and inversely proportional to the square of their distance apart. It is also known as inverse square law.
Permittivity of Free Space vacuum
https://youtu.be/mtkzGd1p0Gw
EVALUATION
1. State four properties of line of force
2. State coulomb’s law
Electric Field Intensity (E)
It is simply the force per unit charge. It is a vector quantity and measured in E = F/Q _________ (iii)
Electric Field Potential (V)
It is the work done in moving a unit positive charge from it point of infinity to a point in the field. It can also be defined as work done per unit charge, it is a scalar quantity and measured in joules per coloumb or volt.
V = W/Q
https://youtu.be/LzKMQByFSLc
Flux Density (D)
It is denoted by D. It is simply charge by unit area. It is measured in Cm-2/ Clm²
D = Q/A
https://youtu.be/-66RypBCs9c
EVALUATION
1. Define (a) electric field intensity (b) electric field potential
2. Differentiate between electric potential and electric potential energy
Reading Assignment : New School Physics pg 72 & 73
ASSIGNMENT
1. The SI unit of flux density is (a) Cm2 (b) Cm (c) Cm-2 (d) C
2. Electric potential is a scalar quantity (a) true (b) false (c) cannot say (d) none of the above
3. Electric field intensity is a scalar quantity (a) true (b) false (c) cannot say (d) none of the above
4. The SI unit of electric potential energy is ………. (a) volt (b) Joules per coulomb (c) Joules (d) Cm2
5. Line of force are maginary (a) true (b) false (c) cannot say (d) none of the above
Theory
1. The force acting on an electron carrying a charge of 1.6X10-19 C in an electric field of intensity 5X108 Vm-1.
2. 1f 20MJ of work is done in moving a5µC of charge between two points in an electric field, the potential difference between the two points is?
TOPIC : Production of Continuous Electric Current
CONTENT
Production of Continuous Current From Mechanical Energy.
Production of Continuous Current From Chemical Energy
Production of Continuous Current From Heat Energy
Production of Continuous Current from Solar Energy.
Production of continuous energy from mechanical energy
When a force is applied at a prime mover, the prime mover drives the amature/ rotar. As the amature is rotating in the magnetic field system , the amature cuts the magnetic flux produce by the magnet. Hence E.M.F will be induced in the coil of the amature based on faraday’s law of electromagnetic induction.
The induced E.M.F can be supplied to an external load.
Production of Continuous Current from Chemical Energy
A cell consist of two dissimilar metals separated by solution of various acids or salt. The metal are known as the electrodes and the solutions are the electrolyte. The positive electrode is known as the anode. The negative electrode is the cathode.
A cell is a device for converting chemical energy into electrical energy.
https://youtu.be/UsHm7X1ckHk
EVALUATION
1. With the aid of a diagram, describe how continuous current can be generated from mechanical energy
2. With the aid of a diagram, describe how continuous current can be generated from chemical energy
Production of Continuous Current from Heat Energy
The ends of two dissimilar metal joined are inserted in cold and hot water and a galvamometer to detect the flow of charges. Due to temperature difference at both end current will flow in the connection. The greater the difference in temperature between the hot and cold junction, the greater the current flow.
Production of Continuous Current from Solar Energy
If solar energy is made to fall on a photo electric cell, solar energy will be converted to electric energy directly by photo electric effect.
https://youtu.be/G5qCw5RIBc0
https://youtu.be/Lh-J1-6ks6g
https://youtu.be/EnYjlsGXugo
EVALUATION
1. With the aid of a diagram, describe how continuous current can be generated from mechanical energy
2. With the aid of a diagram, describe how continuous current can be generated from chemical energy
Reading Assignment : New School Physics pg 75 - 77
ASSIGNMENT
1. Cell convert chemical energy into ________ energy (a) mechanical (b) electrical
(c) solar (d) atomic
2. DC generator convert (a) electric to mechanical energy (b) mechanical to electric energy
(c) solar to electrical energy (d) none of the above
3. Thermocouple consist of two (a) similar metals (b) dissimilar metals (c) alloys metals (d) none of the above.
4. The feature that produces magnetic flux in a generator is ______ (a) Amature (b) magnet (c) stator
(d) prime mover
5. Conversion of mechanical energy into electrical energy in a dc generator is base on what principle
(a) moment (b) faraday’s law of electromagnetic induction (c) coulomb’s law (d) fundamental law of electrostatic.
THEORY
1. With the aid of a diagram, describe how mechanical energy is converted to electrical energy.
2. With the aid of a diagram, describe how heat energy is converted to 5electrical energy
CONTENT:
Concept of Field
Types of Field
Gravitational Field
Concept of Field
Field can be defined as the region or space under the influence of some physical agency such as gravitational, electricity and magnetism.
Types of Field
Fields are of various types namely: gravitational, magnetic and electric field.
Gravitational Field
Gravitational field is any region or space around a mass in which the gravitational force of the mass is felt.
Newton’s law of gravitational states that the force of attraction between two bodies of mass M and m is inversely proportional to the square of their distance R, between their centers and it is directly proportional to the product of their mass.
Mathematical expression:
https://youtu.be/5N_BkadurZA
EVALUATION
1. Define field
2. State Newton law of gravitation
Gravitational Potential
Work is done when mass are moved from one point in a gravitational field to a higher point. Consider a mass (m), raised to a vertical height h from the surface of the earth. The gravitational potential energy = mgh.
Gravitational potential V is stated as the product of universal gravitational constant (G) and the mass (M) to the distance (R) apart.
Mathematically expressed
V = GM/R
https://youtu.be/kFseruQ8YMo
EVALUATION
1. Define gravitational potential
2. Define gravitational field
Reading Assignment : New School Physics pg 67 - 70
ASSIGNMENT(THEORY)
1. Define (a) gravitational field (b) acceleration due to gravity. How does acceleration vary with latitude
2. (a) Explain what is meant by a field as used in physics. (b) Mention three types of field known to you
TOPIC : Electric Field – Line of Forces, Properties of Line of Force, Description and Properties of Force Field
CONTENT
Electric Field
Line of Force and properties
Electric Field
It is simply the space or region around an electric charge where a force is experienced. There are two types of charges namely : positive and negative charges.
Properties of Line of Force.
1. They are imaginary
2. They do not cross each other
3. They begin with a positive charge and end with a negative charge.
4. Electric flux representing uniform field are straight parallels and uniformly space.
5. While the one representing in non uniform field are curves
Coloumb’s Law states that the force experience by two charges Q1Q2 separated by a distance r is directly proportional to their product of their charges and inversely proportional to the square of their distance apart. It is also known as inverse square law.
Permittivity of Free Space vacuum
https://youtu.be/mtkzGd1p0Gw
EVALUATION
1. State four properties of line of force
2. State coulomb’s law
Electric Field Intensity (E)
It is simply the force per unit charge. It is a vector quantity and measured in E = F/Q _________ (iii)
Electric Field Potential (V)
It is the work done in moving a unit positive charge from it point of infinity to a point in the field. It can also be defined as work done per unit charge, it is a scalar quantity and measured in joules per coloumb or volt.
V = W/Q
https://youtu.be/LzKMQByFSLc
Flux Density (D)
It is denoted by D. It is simply charge by unit area. It is measured in Cm-2/ Clm²
D = Q/A
https://youtu.be/-66RypBCs9c
EVALUATION
1. Define (a) electric field intensity (b) electric field potential
2. Differentiate between electric potential and electric potential energy
Reading Assignment : New School Physics pg 72 & 73
ASSIGNMENT
1. The SI unit of flux density is (a) Cm2 (b) Cm (c) Cm-2 (d) C
2. Electric potential is a scalar quantity (a) true (b) false (c) cannot say (d) none of the above
3. Electric field intensity is a scalar quantity (a) true (b) false (c) cannot say (d) none of the above
4. The SI unit of electric potential energy is ………. (a) volt (b) Joules per coulomb (c) Joules (d) Cm2
5. Line of force are maginary (a) true (b) false (c) cannot say (d) none of the above
Theory
1. The force acting on an electron carrying a charge of 1.6X10-19 C in an electric field of intensity 5X108 Vm-1.
2. 1f 20MJ of work is done in moving a5µC of charge between two points in an electric field, the potential difference between the two points is?
TOPIC : Production of Continuous Electric Current
CONTENT
Production of Continuous Current From Mechanical Energy.
Production of Continuous Current From Chemical Energy
Production of Continuous Current From Heat Energy
Production of Continuous Current from Solar Energy.
Production of continuous energy from mechanical energy
When a force is applied at a prime mover, the prime mover drives the amature/ rotar. As the amature is rotating in the magnetic field system , the amature cuts the magnetic flux produce by the magnet. Hence E.M.F will be induced in the coil of the amature based on faraday’s law of electromagnetic induction.
The induced E.M.F can be supplied to an external load.
Production of Continuous Current from Chemical Energy
A cell consist of two dissimilar metals separated by solution of various acids or salt. The metal are known as the electrodes and the solutions are the electrolyte. The positive electrode is known as the anode. The negative electrode is the cathode.
A cell is a device for converting chemical energy into electrical energy.
https://youtu.be/UsHm7X1ckHk
EVALUATION
1. With the aid of a diagram, describe how continuous current can be generated from mechanical energy
2. With the aid of a diagram, describe how continuous current can be generated from chemical energy
Production of Continuous Current from Heat Energy
The ends of two dissimilar metal joined are inserted in cold and hot water and a galvamometer to detect the flow of charges. Due to temperature difference at both end current will flow in the connection. The greater the difference in temperature between the hot and cold junction, the greater the current flow.
Production of Continuous Current from Solar Energy
If solar energy is made to fall on a photo electric cell, solar energy will be converted to electric energy directly by photo electric effect.
https://youtu.be/G5qCw5RIBc0
https://youtu.be/Lh-J1-6ks6g
https://youtu.be/EnYjlsGXugo
EVALUATION
1. With the aid of a diagram, describe how continuous current can be generated from mechanical energy
2. With the aid of a diagram, describe how continuous current can be generated from chemical energy
Reading Assignment : New School Physics pg 75 - 77
ASSIGNMENT
1. Cell convert chemical energy into ________ energy (a) mechanical (b) electrical
(c) solar (d) atomic
2. DC generator convert (a) electric to mechanical energy (b) mechanical to electric energy
(c) solar to electrical energy (d) none of the above
3. Thermocouple consist of two (a) similar metals (b) dissimilar metals (c) alloys metals (d) none of the above.
4. The feature that produces magnetic flux in a generator is ______ (a) Amature (b) magnet (c) stator
(d) prime mover
5. Conversion of mechanical energy into electrical energy in a dc generator is base on what principle
(a) moment (b) faraday’s law of electromagnetic induction (c) coulomb’s law (d) fundamental law of electrostatic.
THEORY
1. With the aid of a diagram, describe how mechanical energy is converted to electrical energy.
2. With the aid of a diagram, describe how heat energy is converted to 5electrical energy