Lesson Note on Physics SS1 Third Term
SCHEME OF WORK
WEEK 1 ELECTRICITY CONCEPT
WEEK 2 RESISTORS
WEEK 3 ELECTRICAL ENERGY AND POWER
WEEK 4 SAFETY DEVICES AND DETECTING FAULTS IN CURRENT
WEEK 5&62022 Physics Lesson Note for Third Term SS1: PARTICULATE NATURE OF MATTER
WEEK 7: SURFACE TENSION
WEEK 8: CAPILLARITY
WEEK 10: ELASTICITY
Physics Lesson Note For SS1 (Third Term)
Below are the 2022 complete Physics lesson notes for SS1 Third Term
Week 1 Topic: Electricity Concept
An electric charge can be at rest or in motion. We speak of static electricity when the charge is at rest, but when the charge is in motion, it is referred to as current electricity.
Electric current, I, is defined as the rate of flow of electric charge along a conductor.
A stream of moving charges (or electrons) constitutes an electric current. We can describe the flow of electric charge along a conductor, e.g. a metallic wire, by expressing it in terms of the section of the conductor in a given time t. The quantity of charge Q is measured in coulombs and the time t in seconds. Hence, current I is given mathematically by the expression. To learn more, click here
Topic: Resistors in Series and Parallel
Circuits consisting of just one battery and one load resistance are very simple to analyze, but they are not often found in practical applications. Usually, we find circuits where more than two components are connected together.
There are two basic ways in which to connect more than two circuit components: series and parallel. First, an example of a series circuit:
Here, we have three resistors (labelled R1, R2, and R3) connected in a long chain from one terminal of the battery to the other. (It should be noted that the subscript labelling — those little numbers to the lower-right of the letter “R” — are unrelated to the resistor values in ohms. They serve only to identify one resistor from another.) The defining characteristic of a series circuit is that there is only one path for electrons to flow. In this circuit, the electrons flow in a counter-clockwise direction, from point 4 to point 3 to point 2 to point 1 and back around to 4. To learn more, click here
Topic: Electrical Energy and Power
Nuclear magnetic resonance (NMR) imaging
Electrical energy is the work done when a quantity of charge moves between two points of potential differences measured in joules.
Work done = Quantity of charge x p.d
W = QV……………………………………(i)
W = Work done, Q = Quantity of charge, V = p.d. across the terminals and we already know that Q =It
Meaning W = (It)v
Where I = Current, V = Voltage, T = Time. To learn more, click here
Topic: Safety Devices and Detecting Faults in Current
Electricity has two hazards. A thermal hazard occurs when there is electrical overheating. A shock hazard occurs when electric current passes through a person. Both hazards have already been discussed. Here we will concentrate on systems and devices that prevent electrical hazards.
This is not how power is distributed in practice. Modern household and industrial wiring requires the three-wire system, which has several safety features. First is the familiar circuit breaker (or fuse) to prevent thermal overload. Second, there is a protective case around the appliance, such as a toaster or refrigerator. The case’s safety feature is that it prevents a person from touching exposed wires and coming into electrical contact with the circuit, helping prevent shocks.
Schematic of a simple AC circuit with a voltage source and a single appliance represented by the resistance R. There are no safety features in this circuit. To learn more, click here
Topic: Structure 0f Matter
Structure of Matter
a. Evidence of the particle nature of matter
The idea that matter is made up of minute particles called atoms dates back to the ancient Greeks. According to the Greek philosopher Democritus, a given piece of substance, say a piece of yam, can be cut into smaller and smaller bits, until eventually the smallest piece of that substance would be obtained which not be further subdivided. This smallest, indivisible, piece was called an atom. The atomic theory of matter assumes that all matter is made up of tiny particles called atoms and that these are all at times in a rapid state of motion. The nature of this motion and its activity depend upon the temperature of matter and other factors.
The experimental evidence of this particle or atomic nature of matter is the Brownian movement, named after the Biologist Robert Brown who was credited with its discovery in 1827. While observing tiny pollen grains suspended in water under a microscope, he noticed that the tiny pollen grains moved about in zig-zag paths even though the water appeared to be perfectly still. The pollen grains were supposed to be jostled or knocked about here and there by the vigorously moving molecules of water. To learn more, click here
Topic: Surface Tension
We observe many things in our day-to-day life. The surface tension Phenomenon is one among them. Often we confuse the Phenomenon of Surface tension with Buoyancy. Both phenomena are entirely different to each other in the sense, in Buoyancy a portion of the body gets dipped in the liquid whereas in Surface tension the body will be remaining on the layer of water without getting wet.
Let us observe these leaves on the surface of the water. We could see them moving in the water without getting wet.
For these leaves to be on the layer, there should be some force acted by the upward layer of water which keeps the leaf on the surface. This is nothing but the Surface tension. Let us study more about Surface tension in this section. To learn more, click here
When we dip three tubes with fine bores but with different diameters into clean water, we observe that water rises in the tubes but the narrower the bore the higher the height to which the rises.
Capillary action (sometimes capillarity, capillary motion, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper, in some non-porous materials such as liquefied carbon fiber, or in a cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container act to lift the liquid. In short, the capillary action is due to the pressure of cohesion and adhesion which cause the liquid to work against gravity. To learn more, click here
Elasticity is the ability of a material to regain its original shape or size after deformation or after removal of stress/force, or after it has been compressed. Deformation occurs when a wire is stretched or compressed. Deformation is elastic if the wire returns to its original position, while it is plastic if it does not return to its original position.
Terms used in Elasticity
1. Elastic limit: Elastic limit is the maximum load (force) that a body can experience and still retain its original size/shape once the load/force has been removed. It can also be defined as “the point on a stress/strain or load/extension graph beyond which Hooke’s law is no longer obeyed.
2. Yield point: Is reached when a stretched wire does not return to its original position
3. Maximum load: When a load is added to a wire that it cannot stand any further increase, it is called maximum load. To learn more, click here