AskPhysics Updates
- Strike while the iron is hot !AskPhysics Blog Feed Dear students, CBSE has given you more time for exams. We have approximately 7 days before the Physics exams. How to use this seven days effectively for a thorough revision is very important. 7-8 days of sleeping is a must. One hour of exercise 1 to 2 hours for break fast lunch […]
- Dreams come true only for those who do their partAskPhysics Blog Feed I was recently narrating the life story of a girl from Dindigul who got married to a police constable at the age of 14. She was not even reached class 10. She became the mother of two kids by the age of 18. During that time she had to accompany her husband […]
- “DID THOSE PHILOSOPHERS WORK IN VAIN”AskPhysics Blog Feed “The Philosophers who worked in search of the Philosophers’ stone and those set themselves dedicated to find the elixir of life”The works of those in search of the Philosopher’s stone didn’t go in vain, They made the beginning. The beginning itself was so wonderful that anyone who got touched by the idea […]
- Quarks, conservation, entanglementAskPhysics Blog Feed Doubt from AskPhysics.comI have heard the following statements-> 1. Quarks always exist in a group of 2 or 3, and can not stand alone. 2. Protons are made up of 2 up quarks, and 1 down quark. 3. Quantum mechanics allows us to entangle a particle by somehow dividing it into 2(For […]
- Prepare for Physics oral test too during lockdownAskPhysics Blog Feed Plus Two Physics Oral Test series Many schools have started oral questioning also as part of diagnostic and formative assessment. The initiative was … Prepare for Physics oral test too during lockdown The post Prepare for Physics oral test too during lockdown appeared first on Ask Physics.
- Theory of RelativityAskPhysics Blog Feed The basic concepts of relativity are explained in a very simplified way that are easy to understood by Mr. Vivek Sawhney in this YouTube Video… The video focuses upon the general discussion on Theory of Relativity….What is the theory of Relativity? What is time dilation and length contraction? SUBSCRIBE to the YouTube […]
- A numerical problem from motion in 1 DimensionAskPhysics Blog Feed A boy plays with a ball on a field surrounded by a fence which has a height of 2.5m . He kicks the ball vertically up from a height of 0.4m with a speed of 14 ms−1. (a) What is the maximum height of the ball above the fence? (b) What is […]
Class XII Physics MCQ for online tests
With teaching taking place mostly online due to Covid-19 threat, MCQ based assessment has become more popular. Here you can download Class XII Physics MCQ for online as well as offline testing. The materials may also be useful for JEE and NEET.
CBSE Class 11 Physics- Study Materials – Physical World
o Scientific method is a way to gain knowledge in a systematic and in-depth way. It involves: o Systematic observations
o Controlled experiments
o Qualitative and Quantitative reasoning
o Mathematical modeling
o Prediction and verification (or falsification) of theories
o Speculation or Prediction
o Science does not have any final theory. The improved observations, accurate tools keep improving the knowledge and perspective. Johannes Kepler used Tyco Brahe’s research on planetary motion to improve Nicolas Copernicus theory.
Download full version of Physical World Study Materials (PDF)Download
Prepare for Physics oral test too during lockdown
Plus Two Physics Oral Test series
Many schools have started oral questioning also as part of diagnostic and formative assessment. The initiative was started after finding that those students who couldn’t score good marks are now scoring very high marks conducted online or offline in flipped mode. To assure whether the students actually know the concepts, the teachers have started asking oral questions as part of evaluation and to justify the score obtained by the students in tests (MCQ or descriptive).
We are starting a series of conceptual Question & Answer series for class 12 Physics, which will help you answer the questions asked orally.
ELECTROSTATICS (Module 1)
- What is frictional electricity?
- What is electrostatics?
- What is static electricity?
- Name two devices which work on the basis of static electricity.
- What is the cause of frictional electricity?
- What is triboelectric series?
- State the principle of quantisation of charge.
- State the principle of conservation of charge.
- Explain additive nature of charge.
- What is the nature of force between unlike charges and like charges?
- State Coulomb’s law.
- What are the limitations of Coulomb’s law?
- State the principle of superposition of electrostatic force.
- What do you mean by linear density of charge?
- What do you mean by surface charge density?
- How can you prove that there are two kinds of charges?
- How can you prove that like charges repel and unlike charges attract?
- What are dielectric and non electric substances?
- What is the effect of placing a dielectric in between two charges on the force between them?
- Define relative permittivity or dielectric constant of a medium?
- What is the value of absolute electric permittivity of free space?
- What is the unit of relative permittivity (or dielectric constant)?
- What is the unit of absolute permittivity?
- Define dielectric constant of a medium in terms of force between two point charges.
- If the force between two point charges of magnitude q each separated by a distance r is F, then how will the force between the two charges be affected if a third point charge 4q is kept at a distance 2r from either of the charges?
(We are not posting the answers now. Please try to answer in the comment box quoting the question number. Alo ask if you don’t know the answers, quoting the question number.)
The Ring Launcher Experiment and Eddy Currents
What are eddy currents?
The video focuses upon the demonstration of the concept of Eddy Currents and the application of Lenz Law, using a device called- RING LAUNCHER
Eddy currents are loops of electrical current induced within solid conductors by a changing magnetic field in the conductor according to Faraday’s law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.
Lenz’s law. A principle stating that an electric current, induced by a source such as a changing magnetic field, always creates a counterforce opposing the force inducing it. This law explains such phenomena as diamagnetism and the electrical properties of inductors.
Lenz’s Law explains the production of eddy current in a changing magnetic field.
Primarily, eddy currents will be introduced in the material, when an electrically conductive material is placed in the coils magnetic field an electromagnetic induction occurs.
The magnitude of the eddy currents produces a large current since the resistance of the metallic conductor becomes low. They may produce undesirable effects if the large eddy current is allowed to in the core of a choke coil, transformer, etc.
By making use of a laminated core, the eddy currents produced in the core of a transformer are reduced. In the present day, electric brakes are provided on the trains in addition to those vacuum brakes.
Electromagnetic Induction for Class 12
EMI: Electromagnetic Induction is the phenomenon in which an emf is produced across the ends of a coil whenever the magnetic flux linked with it changes.
Induced EMF
the EMF induced across the ends of a coil due to change in the magnitude of magnetic flux linked with it is called induced emf
Induced Current
If the coil is in a closed circuit, and whenever the magnetic flux linked with it changes, a current flows through it. This current flowing through a coil in a closed circuit due to the change in magnetic flux linked with it is called induced current.
Kinematics: Equations of uniformly accelerated Motion
Watch the following video to understand Kinematic Equations for uniformly accelerated motion
Physics Study Materials fr Class XII
You can download here the Physics study materials for class XII CBSE Physics. The material will be useful for revision for AISSCE 2020 and afterwards.
http://plustwophysics.com/wp-content/uploads/2020/01/Physics_SM.pdf