GRADE 10 SCIENCE CLASS

[Virtual Presenter] Good morning! My brilliant students! (voice-emphasis: strong) (pause: 1) Good morning, Ma’am. (voice-emphasis: strong) (pause: 1) How are you feeling today? (voice-emphasis: moderate) (pause: 1) We’re fine ma’am. (voice-emphasis: moderate) (pause: 1) Glad to hear! (voice-emphasis: none).

[Audio] Ok, everyone! What do you see in this slide? (voice-emphasis: strong) (pause: 1) Mr. Cabigas, What do you observe in the pictures/gifs? (voice-emphasis: moderate) (pause: 1) Yes Ma'am, I see objects with rotating mechanism (voice-emphasis: none) (pause: 1) Very good, Mr. Cabigas. (pause: 1) Yes, your answer is correct! they rotate, and our topic for today is all about Electric motors. (voice-emphasis: strong) (pause: 1) Let's have a guessing game first. Let's divide the class into two. Each group will be given set of puzzles for you to arrange and come up with the correct image. (pause: 1) Okay let's start! I will give you 5 minutes to arrange it and after that, each group will present their answers. (pause: 1) Are you ready! Time starts in 3, 2, 1, Go! (voice-emphasis: strong) (pause: 2) Are you all finished? (voice-emphasis: none) (pause: 1).

[Audio] Here is an image of Electric motor, also showing its cross section. (voice-emphasis: moderate) (pause: 1) Is this the same image that you have formed with your puzzles? (voice-emphasis: none) (pause: 1).

[Audio] Okay, let us now proceed to identifying its basic parts. (voice-emphasis: moderate) (pause: 1) For the instruction, each group will be given a picture and the names of the parts of an electric motor. Each group must attach those words to the appropriate image. There are hints at the back of those words, so don't use Google. (voice-emphasis: none) (pause: 1).

[Audio] Your timer, starts (voice-emphasis: moderate) (pause: 1) NOW! (voice-emphasis: strong) (pause: 2).

[Audio] VOCABULARY: (voice-emphasis: strong) (pause: 1) Electromagnetism- is the physical interaction among electric charges, magnetic moments, and the electromagnetic field. (pause: 1) Electricity- the flow of electrical power or charge. (pause: 1) Magnetism- a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects. (pause: 1) Magnetic Field- a region around a magnetic material or a moving electric charge within which the force of magnetism acts (voice-emphasis: none) (pause: 1).

[Audio] Our topic for today is all about Electric Motor. (voice-emphasis: strong) (pause: 1).

[Audio] Electric motor-is a device used to convert electricity into mechanical energy or motion. (voice-emphasis: moderate) (pause: 1) Is a type of prime mover for a mechanical system. (voice-emphasis: none) (pause: 1).

[Audio] It was first developed by William Sturgeon in 1832. (voice-emphasis: moderate) (pause: 1) William Sturgeon was an English electrical engineer who devised the first electromagnet capable of supporting more than its own weight. (voice-emphasis: moderate) (pause: 1) This device led to the invention of the telegraph, the electric motor, and numerous other devices basic to modern technology. (voice-emphasis: none) (pause: 1).

[Audio] What we have here are examples of an electric motor found or used in different applications. (pause: 1) First, we have an electric motor of a washing machine. It is normally located at the bottom of the appliance. (pause: 1) Second is the electric motor of a blender. Attached to its main shaft are the blades which cuts whatever is placed in it. (pause: 1) Third, is an electric motor of a fan, which very common as we can see it everywhere. (pause: 1) Last is an example of an electric motor of a car. This is one of the plenty electric motors that can be found in a car. (pause: 1).

[Audio] Basic parts of an electric motor: (voice-emphasis: strong) (pause: 1) First, Stator (voice-emphasis: strong) (pause: 1) The stationary part of the motor, specifically the magnet. (voice-emphasis: moderate) (pause: 1) Now, let's go back to your answers and check them. (voice-emphasis: none) (pause: 1) Are your answers correct? (pause: 1).

[Audio] Second, Rotor: (voice-emphasis: strong) (pause: 1) The coil that is mounted on an axle and spins at high speeds, providing rotational, mechanical energy to the system. (voice-emphasis: moderate) (pause: 1) Are your answers correct? (voice-emphasis: none) (pause: 1).

[Audio] Third, Commutator. (voice-emphasis: strong) (pause: 1) The commutator allows the rotor to spin by reversing the current each time the coil does a half turn. (voice-emphasis: none) (pause: 1).

[Audio] Fourth, Bearings. (voice-emphasis: strong) (pause: 1) Bearings support the rotor and allow the rotor to spin on its axis. The motor housing in turn supports the bearings. (voice-emphasis: none) (pause: 1).

[Audio] Fifth, Brushes. (voice-emphasis: strong) (pause: 1) These are connected to the terminals of the power source, allowing electric power to flow into the commutator. (voice-emphasis: none) (pause: 1).

[Audio] Sixth, Shaft. (voice-emphasis: strong) (pause: 1) Is a cylindrical component that extrudes out from the motor and its housing. (voice-emphasis: none) (pause: 1).

[Audio] How do electric motors work? (voice-emphasis: strong) (pause: 1) Danish Physicist Hans Christian Ørsted began a new scientific era when he discovered that electricity and magnetism are linked. (voice-emphasis: moderate) (pause: 1) He showed by experiment that an electric current flowing through a wire could move a nearby magnet. (voice-emphasis: none) (pause: 1).

[Audio] Motors work through the principles of (pause: 1) ELECTROMAGNETISM. (voice-emphasis: strong) (pause: 1) Again, Ms. Mendez, what is electromagnetism? (voice-emphasis: moderate) (pause: 1) Electromagnetism- is the physical interaction among electric charges, magnetic moments, and the electromagnetic field. (voice-emphasis: none) (pause: 1) Electric motor follows the principle that the current-carrying conductor produces a magnetic field around it. (voice-emphasis: moderate) (pause: 1) Thank you. Ms. Mendez (voice-emphasis: none) (pause: 1).

[Audio] Electric motor follows the principle that "the current-carrying conductor produces a magnetic field around it." (voice-emphasis: moderate) (pause: 1).

[Audio] In this figure, there is an attraction, we all know, that unlike poles attract while like poles repel. (pause: 1) Since they have unlike poles, the South pole grabs the North pole and vice versa. (pause: 1) However, it can't rotate continuously if we set it to unlike poles always because there is a permanent attraction. (pause: 1) So, do we need to change the polarity? (pause: 1) What is polarity? (voice-emphasis: strong) (pause: 1).

[Audio] Polarity (voice-emphasis: strong) Is the directional flow of electrons from one pole to the other. (voice-emphasis: none) (pause: 1) It is when an entity contains two distinct and opposite poles that can either attract or repel each other. (pause: 1) So, if we reverse the polarity of our electromagnet then this will happen. (pause: 1).

[Audio] There is a repulsion since the south pole pushes away the other south pole, and the N pole pushes the other N pole. (pause: 1) For every half-turn, we need to reverse the polarity. (pause: 1) So, they repel and attract, repel and attract. In order to have a continuous rotation. (pause: 1) To understand more the basic operation or principle of a simple electric motor let's see this short video. (pause: 1).

[Audio] As you can see in the video, the current flows through the induction coil or the spark coil this is to generate a high-frequency electromagnetic field meaning the electric motor works on the principle that when a coil is placed in the magnetic field and the current passes through it, would result to the rotation of the coil. (voice-emphasis: moderate) (pause: 1) Now, let's further watch the relationship between electricity and magnetism in order for the electric motor to rotate. (voice-emphasis: none) (pause: 1).

[Audio] So, again how do electric motors work? (pause: 1) Motors work through the principles of ELECTROMAGNETISM. (voice-emphasis: strong) (pause: 1) "If you run electricity through a wire, it creates a magnetic field." (voice-emphasis: moderate) (pause: 1) If there's no electricity then there is no electromagnet, and the rotation will stop. (pause: 1) That's their relationship or connection. (pause: 1) That's why our appliances such as fans, blowers, blenders, and washing machines won't function without electricity. (voice-emphasis: none) (pause: 1) Am I understood? (voice-emphasis:strong) (pause: 1).

[Audio] Again, Electric motors work through the principle of Electromagnetism that stated. (voice-emphasis: strong) (pause: 1) "If you run electricity through a wire, it creates a magnetic field." (voice-emphasis: none) (pause: 1).

[Audio] The applications of electric motors primarily include fans, blowers, machine tools, turbines, pumps, power tools, compressors, alternators, rolling mills, movers, ships, and paper mills. (pause: 1) The electric motor is an important device in various applications like cooling & ventilating equipment, motor vehicles, and home appliances. (pause: 1).

[Audio] Your Assignment: (voice-emphasis: strong) (pause: 1) On your 1/2 sheet of paper, write down the two types of electric motors and utilize the Venn diagram to show their relationship. (voice-emphasis: none) (pause:1).

[Audio] Okay, What we have is the rubrics for the assessment. (voice-emphasis: strong) (pause: 1) Please Read carefully, before answering. (voice-emphasis: none) (pause: 1).

[Audio] And, Thank you Class for listening. (voice-emphasis: moderate) (pause: 1).