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Wednesday, November 28, 2018

Capacitor & Dielectrics 4

  8:50 PM    Rohit



q Electrons will flow out from the negative terminal of the battery, through the resistor R and accumulate on the plate B of the capacitor.
q Then electrons will flow into the positive terminal of the battery, leaving a positive charge on the plate A.
q As charge accumulates on the capacitor, the potential difference across it increases and the current is reduced until eventually the maximum voltage across the capacitor equals the voltage supplied by the battery, Vo.
q At this time, no further current flows (I = 0) through the resistor R and the charge Q on the capacitor thus increases gradually and reaches a maximum value Qo

V0 = VR + VC, VR = IR, VC = Q/C
At t = 0, V0 = VR, VC = 0

During charging, V0 = IR + Q/C, I in resistor decreasing, Q in capacitor increasing
As t ® ¥, V0 = VC, VR = 0

•Initially, the potential difference (voltage) across the capacitor is maximum, V0 and then a maximum current I0 flows through the resistor R.
•When part of the positive charges on plate A is neutralized by the electrons, the voltage across the capacitor is reduced.
•The process continues until the current through the resistor is zero.
•At this moment, all the charges at plate A is fully neutralized and the voltage across the capacitor becomes zero.

V0 = VR + VC, VR = IR, VC = Q/C
At t = 0, V0 = VC, VR = 0
During discharging, V0 = IR + Q/C, I in resistor decreasing, Q in capacitor decreasing
As t ® ¥, V0 = VR, VC = 0

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Capacitor & Dielectrics 3

  7:49 PM    Rohit






Consider a parallel-plate capacitor
 
·       Initially the plates are separated by a vacuum and connected to a battery, giving the charge on the plates +Q and –Q
·       The battery is now removed and the charge on the plates remains constant
·       The electric field between the plates is uniform and has a magnitude of E0
·       Meanwhile the separation between plates is d
·       When a dielectric is placed in the electric field between the plates, the molecules of the dielectric tend to become oriented with their positive ends pointing toward the negatively charged plate and vice versa
·       The result is a buildup of positive charge on one surface of the dielectric and of negative charge on the other
·       The number of field lines within the dielectric is reduced thus the applied electric field E0 is partially canceled
·       The new electric field, E is electric field between the plates is uniform and has a magnitude of E0
·       The new electric field strength (E < E0) is less, then the potential difference, V across the plates is less
V = Ed
·       Since V is smaller while Q remains the same the capacitance
C = Q/V
       is increased by the dielectric

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Monday, November 26, 2018

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Friday, November 9, 2018

IR 4.0/ Education

  11:59 PM    Rohit

There are 9 trends that stand out:
  1. Diverse time and place.Students will have more opportunities to learn at different times in different places. eLearning tools facilitate opportunities for remote, self-paced learning. Classrooms will be flipped, which means the theoretical part is learned outside the classroom, whereas the practical part shall be taught face to face, interactively.
  2. Personalized learning.Students will learn with study tools that adapt to the capabilities of a student. This means above average students shall be challenged with harder tasks and questions when a certain level is achieved. Students who experience difficulties with a subject will get the opportunity to practice more until they reach the required level. Students will be positively reinforced during their individual learning processes. This can result in to positive learning experiences and will diminish the amount of students losing confidence about their academic abilities. Furthermore, teachers will be able to see clearly which students need help in which areas.
  3. Free choice.Though every subject that is taught aims for the same destination, the road leading towards that destination can vary per student. Similarly to the personalized learning experience, students will be able to modify their learning process with tools they feel are necessary for them. Students will learn with different devices, different programs and techniques based on their own preference. Blended learning, flipped classrooms and BYOD (Bring Your Own Device) form important terminology within this change.
  4. Project based.As careers are adapting to the future freelance economy, students of today will adapt to project based learning and working. This means they have to learn how to apply their skills in shorter terms to a variety of situations. Students should already get acquainted with project based learning in high school. This is when organizational, collaborative, and time management skills can be taught as basics that every student can use in their further academic careers.
  5. Field experience.Because technology can facilitate more efficiency in certain domains, curricula will make room for skills that solely require human knowledge and face-to-face interaction. Thus, experience in ‘the field’ will be emphasized within courses. Schools will provide more opportunities for students to obtain real-world skills that are representative to their jobs. This means curricula will create more room for students to fulfill internships, mentoring projects and collaboration projects (e.g.).
  6. Data interpretation.Though mathematics is considered one of three literacies, it is without a doubt that the manual part of this literacy will become irrelevant in the near future. Computers will soon take care of every statistical analysis, and describe and analyse data and predict future trends. Therefore, the human interpretation of these data will become a much more important part of the future curricula. Applying the theoretical knowledge to numbers, and using human reasoning to infer logic and trends from these data will become a fundamental new aspect of this literacy.
  7. Exams will change completely.As courseware platforms will assess students capabilities at each step, measuring their competencies through Q&A might become irrelevant, or might not suffice. Many argue that exams are now designed in such a way, that students cram their materials, and forget the next day. Educators worry that exams might not validly measure what students should be capable of when they enter their first job. As the factual knowledge of a student can be measured during their learning process, the application of their knowledge is best tested when they work on projects in the field.
  8. Student ownership.Students will become more and more involved in forming their curricula. Maintaining a curriculum that is contemporary, up-to-date and useful is only realistic when professionals as well as ‘youngsters’ are involved. Critical input from students on the content and durability of their courses is a must for an all-embracing study program.
  9. Mentoring will become more important.In 20 years, students will incorporate so much independence in to their learning process, that mentoring will become fundamental to student success. Teachers will form a central point in the jungle of information that our students will be paving their way through. Though the future of education seems remote, the teacher and educational institution are vital to academic performance.
  10. More on: Education 4.0 … the future of learning will be dramatically different, in school and throughout life.

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Thursday, November 8, 2018

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