Module 3_General Physics 2 electric.pptx

A PowerPoint presentation about the lesson in General Physics 2.

1. General Physics 2 Grade 12-STEM B

2. Class Policies 1. Listen to your teacher. 2. Avoid unnecessary noises. 3. Pay attention when someone is talking. 4. Raise your hand if you want to answer. 5. Always follow instructions.

3. Review! 1. What are the two classifications of materials ? 2. What are the two types of charging ? 3. What is the mathematical formula for Coulomb’s Law ?

4. Game: My Graffiti Wall Materials: Cartolina and Crayons Procedure : • The class will be divided into four groups. Each group must have the materials in writing their answers. • The teacher will read the questions then in 3 seconds, each group will write their answer to the cartolina . • Afterwards , the teacher will count another 5 seconds then the cartolina will move counterclockwise. • The group must work collaboratively to answer every questions being ask.

5. Capacitance and Dielectric Effects Lesson 4

6. Learning Objectives: • Describe capacitance and dielectric through charged and discharged; • Realize the different uses of dielectric and capacitance in daily living; and • Calculate the capacitance of parallel-plate and dielectric on various materials at room temperature.

7. Activity: Capacitor Lab: Basic Objective: Describe relationships between the capacitance, charge, voltage, and store energy through an online simulation . Retrieved from : https:// phet.colorado.edu/sims/html/capacitor-lab-basics/latest/capacitor-lab-basics_en.html

8. Activity: Capacitor Lab: Basic Procedure : You will visit the PhET simulation “Capacitor Lab: Basic” to investigate the relationship between the capacitance, charge, voltage, and the stored energy in a capacitor. On the upper panel, check the “Top Plate Charge” and “Stored Energy”. Check the “Electric field” on the right panel, to see the electric field lines. Drag the “Voltmeter” from the right panel, connect the positive (red) lead to the upper plate and negative (black) lead to the lower plate. Keep the dimensions of the capacitor constant in this activity; the separation between the plates is 0.6 mm and the plate areas is 200 mm².

9. Activity: Capacitor Lab: Basic Procedure : Move the slider on the battery up in order to increase the battery voltage from 0 V to 1.5 V. Notice that increasing the voltage of the battery also changes the voltage between the plates of the capacitor, and the capacitor will be charged very quickly (almost instantly). For the given values of the voltage between the plates, measure and record the corresponding capacitance, charge, and stored energy in the following table.

10. Activity: Capacitor Lab: Basic Voltage between plates (V) Capacitance (pF) Plate Charge (pC) Stored Energy(pJ)       0.2       0.4       0.6       0.8       1.2       1.5      

11. Activity: Capacitor Lab: Basic Guide Questions: How does the voltage between the plates relate to the battery voltage ? Is the capacitance affected by charging the plate charge or the voltage between the plates?

12. Capacitance Lesson 4

13. Capacitor A capacitor is a device which stores electric charge. Capacitors vary in shape and size, but the basic configuration is two conductors carrying equal but opposite charges . A capacitor may also act as a switching, mechanism in an electric circuit.

14. Capacitor The simplest capacitor consists of two metal plates parallel to each other and separated by a distance which is small compared with the area of each plate. This type of capacitor is called a parallel-plate capacitor . Whereas, the insulating material that separates one plate from the other is called Dielectric.

15. The Capacity of the Capacitor In mathematical form: Capacitance = Charge/ Potential Difference or C=Q/V where; C = capacitance of the capacitor, measured in Farads, F Q = charge of each plate, measured in Coulombs, C V = applied voltage, measured in volts, V The capacitance of a capacitor is a measure of how much electrical energy the capacitor can store when a certain voltage is applied to it. Three Quantities Capacitance Charge Applied Voltage 01 02 03

16. The Units of the Capacitor Many capacitors can store electric charge in the microcoulomb range: 1 microfarad = 1uF= 1x10ˉ⁶ F 1 nanofarad = 1 nF = 1X10ˉ⁹ F 1 picofarad = 1 pF = 1X10ˉ¹² F The unit of the capacitance is expressed in farads (F ). A capacitance pf 1 farad (1F) if one coulomb of charge is produced in the capacitor when potential difference of one volt is applies across the plates of the capacitor.

17. Factors Affecting the Capacitance E=σ/Ꜫₒ where; σ = magnitude of the surface charge density on either plate, C/m² = Q/A Ꜫₒ = permittivity of free space = 8.85x10ˉ¹² F/m The capacitance may be increased or decreased by changing some of its physical characteristics. The magnitude of the electric field is given by the equation:

18. Types of Capacitors Variable Capacitors and Fixed Capacitors

19. Types of Capacitors Variable Capacitors As the name implies, is one in which the capacitance can be changed. It can be represented by the symbol . Types: Rotor-Stator Trimmers Fixed Capacitors The capacitance of fixed capacitors as manufactured can no longer be varied . Types: Paper Tubular Ceramic Mica Electrolytic

20. Variable Capacitors Rotor-Stator. This is sometimes called as tuning capacitor that is used for tuning radio receivers. Trimmers. This consists of two metal plates separated by a thin piece of mica.

21. Fixed Capacitors Paper Tubular. This capacitor consists of thin aluminum foil plate separated by waxed paper. Ceramic. The dielectric is made of ceramic (clay) material that is mixed with titanium dioxide.

22. Fixed Capacitors Mica . The dielectric material between the plates of this capacitor is mica. These are usually used for small capacitance and they have very high voltage rating. Electrolytic. The capacitor consists of one aluminum plate having one side covered with chemical electrolyte solution, and a second aluminum foil, main function is to make electrical contact with the electrolyte.

23. Dielectric Effects

24. Dielectric Any non-conducting material is called a dielectric. The charge of dielectric is called bound charge which is capable of effecting a slight displacement when placed in an electric field.

25. Effects of Dielectric When a dielectric is inserted between the plates of a charged capacitor, its capacitance is increased. C will increase only if any of the following conditions is satisfied: Charge Q , increases while the potential difference V remain constant; the potential difference V decreases while Q remain constant. The original electric field, Eₒ, can be expressed in terms of the original potential difference, Vₒ, between the plates and their separation distance d. Eₒ = Vₒ/ d or Vₒ = Eₒ d

26. Effects of Dielectric The effectiveness of a dielectric in reducing the electric field which results in increased capacitance can be expressed in terms of the dielectric constant, K. the dimensionless factor is defined as: If you expressed the electric field in terms of the potential difference, equation can be written as :  

27. Recap! What is a capacitor? What are the two classifications of capacitors and their types? What is a dielectric? What are the conditions on the effects of dielectric?

28. Let’s Apply! A capacitor is rated 0.0002 F. What is the capacitance in: uF nF pF ?

29. Quiz Time! Test I. Problem Solving Instruction: Solve the following problems completely and neatly. Write your solution in a clean sheet of intermediate or yellow paper. 1. A capacitor has square plates. Each side of length 10 cm. the plates are spaced 1 cm apart. If the capacitor is connected to a 12-volt battery, a .) calculate the capacitance of the capacitor. b .) charge on each plate c .) electric field between the plate.