12P01 Electric Charges and Fields

 Step-by-step


Step 1: Theory and Concepts

Step 2: Numerical Practice
NCERT Examples, NCERT Exercises with solutions

Step 3: Numerical Practice
Chapterwise CBSE Past papers (Any one of them- Arihant, MTG, XAM Idea etc.)

Step 4: Numerical Practice

Step 5: Numerical Practice
JEE Main past year Questions, Solutions



Two charges and Forces between them.
Plot F vs. r graph to see the shape of the graph.


How to solve Numerical problem in physics?

 

How to solve Numerical problem in physics?

“Start walking. The path will become clearer”


 Step 1: Translating from English language to Maths and Drawing.

·        Nature is written in the language of Mathematics. Drawing is the language of Engineers and Scientists.

·        Read the question line by line converting it into a simple cartoon diagram or a mathematical expression. Mark the numerical values in appropriate places in the diagram or with the mathematical notations.

 Step 2: Understand what is given and what is to be found.

One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face forms an image 12 cm behind the silvered face. The refractive index of the glass is

One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face forms an image 12 cm behind the silvered face. The refractive index of the glass is

A) 0.4     B) 0.8    C) 1.2     D) 1.6

12P02 Electric Potential and Capacitance



Understand how much distance I have to move to cause a voltage difference of 1 V 
a) Far away from the source charge b) Very close to the source charge. 
Connect that finding with Conservative Force / Field concepts
$E= - \frac{dV}{dr} \; \;  F = -\frac{dU}{dr}$


Equipotential Lines for two charges separated by a distance 
a) oppositely charged b) same charged

 



Capacitor Basics
Change the battery voltage and see what happens to 
the charge and the voltage in the capacitor, Q = C V
Change the area and gap between the plates and see what happens 
to the Capacitance value, C = epsilon_o A / d

12P07 Alternating Current

  



Virtual Oscilloscope to try different waveforms and also to input your own voice.
From the seconds/div calculate the frequency of the wave and double check the value.
What is the formula or relation between time period, frequency, angular frequency?

In a double slit experiment two coherent beams have slightly different intensities I and $\delta I$. Show that the resultant intensity at the maxima is nearly 4I, while that at the minima is $(\delta I)^2/4I$

In a double slit experiment two coherent beams have slightly different intensities I and $\delta I$. Such that I >>$\delta I$. Show that the resultant intensity at the maxima is nearly 4I, while that at the minima is $(\delta I)^2/4I$

Courtesy:ophysics.com
For Intensity at Maxima,
\[ I=I_1+I_2+2\sqrt{I_1 I_2}\cos\phi \]
\[I_{max}=I+\left(I+\delta I\right)+2\sqrt{I(I+\delta I)}\cos 0\]
\[=2I+\delta I+2I\left(1+\frac{\delta I}{I}\right)^{\frac{1}{2}}\]
\[=2I+\delta I+2I\left[1+\frac{1}{2}\frac{\delta I}{I}+\frac{\frac{1}{2}.\frac{-1}{2}}{2}\left(\frac{\delta I}{I}\right)^2\right]\]
Using Binomial theorem, ignoring the higher order terms, $(\frac{\delta I}{I})^{2}$
\[=4I+2\hspace{2mm}\delta I\]
\[\approx4I\]

FAQs by parents for Physics Class

"Teacher does not teach. 
   Student learns. 
   Teacher just helps in the process of learning."


Frequently asked questions for Physics Class

1) Sir, we heard you have stopped taking class. Are you by any chance taking classes?
Due to some throat pain issues, I took a break from classes from March 2024 to Sep 2024. Even now beyond 45 min, I am not able to speak comfortably, especially physics being a subject where one has to speak and explain a lot. So I am teaching few students coming to my home.

12P14 Semiconductor Study Notes



        Crystal Lattice and Logic Gates Study Notes -- PDF Notes




Interaction with 3D Models for Crystal Lattice SCC BCC FCC

Quantity of water or liquid flowing out of a tank through a hole orifice at the bottom of the tank. Mathematical Modelling and Experimental Results.

Quantity of water or liquid flowing out of a tank through a hole orifice at the bottom of the tank. Mathematical Modelling and Experimental Results.

Application of Integration methods to model quantities that are changing continuously in a non-linear fashion with respect to time.

This work was started as a way to illustrate the power of calculus in mathematical modelling to class 11 and 12 students, when we deal with quantities that are not changing linearly with respect to time or other variable. However the integration methods look slightly complicated and may be suitable only for college level students and fluid mechanics students.

Mathematical Model PDF File

Excel Calculations and Graphs Excel File



What is the difference between Boiling and Evaporation? Gas and Vapour?

 What is the difference between Boiling and Evaporation? Gas and Vapour?

Edited and Contributed by
R Kesavamurthi
Founder
IGNITING YOUNG MINDS (IYM)
9952419531
https://ignitingyoungminds.in



Qn1: What is difference between boiling and evaporation ?

Qn2: Why do we sprinkle water on the roof or open ground in summer?

Qn3: What is the difference between gas and vapour?

 

Why Soap Bubbles Liquid drops take spherical shape ? Surface Tension Experiments Soap film taking minimum area

11P09D Surface Tension / Mechanical Properties of Fluids

Why Soap Bubbles, Liquid Drops take Spherical Shape ? Soap Film taking minimum Area.

Surface Tension is one topic that is slightly difficult for the students. Simple home experiments can help to grasp the idea.


Students Shreya and Jagan Surface Tension Experiments

NCERT Exercise 3.15 An aircraft executes a horizontal loop of radius 1.00 km with a steady speed of 900 km/h. Compare its centripetal acceleration with the acceleration due to gravity. What is G Force?

NCERT Exercise 3.15 An aircraft executes a horizontal loop of radius 1.00 km with a steady speed of 900 km/h. Compare its centripetal acceleration with the acceleration due to gravity.

v = 900 km/h = 250 m/s

Centripetal Acceleration,
ac = v2/r = 2502 /1000 = 62.5 m/s2 
g = 9.8 m/s2  
ac = 6.4 g (6.4 times the gravitational acceleration)




What is G Force?

Student John Paul Anto's Microwave Oven Experiment - Experimental verification of speed of Electromagnetic waves

 12P08 Electromagnetic Waves

Student John Paul Anto's Microwave Oven Experiment - Experimental verification of speed of Electromagnetic waves

 

If you have access to a microwave oven, see if you can do this simple 10 minutes experiment in your microwave.

1. Remove the turn table inside the oven

2. Place an uncooked Chappathi (Tortila) or similar flour item spread out

3. Switch on the oven for a nominal time ( may be 1 minute or 2 minutes as required)

4. Open the oven and look for any black spots where the heat is concentrated

5. Measure the distance between the black spots using a measuring scale (few cm expected)

6. In the instrument label in the back side of oven look for any frequency of microwaves used.

7. We are looking for the Speed of Microwave c = Frequency x Lambda, calculations from the above values obtained.

8. Any videos or pictures of the experiment will be very helpful for educational purpose may be to upload in youtube.

 

Microwave is an Electromagnetic wave. All EM waves such as light, radio wave, microwave, infrared wave, uv rays, x rays, gamma rays travel at the speed of light c = 3 x 108 m/s. This experiment is an attempt to experimentally verify the speed of microwaves.

 

 

Before Heating


After Heating, approx.6 cm gap between black spots

Student Swetha's Apparent Weight Experiments in Lift

 11P04 Newton's Laws of Motion

Student Swetha's Apparent Weight Experiments in Lift

(Class 11 student 2023-24)



Actual reading before getting on the lift: 50 kg shown. 
This is approx. 500 N due to gravity alone. Fg = mg = (50) (10) = 500 N.

Student Hashmitha's Double Slit Experiments YDSE

 12P10 Wave Optics: Student Hashmitha's Experiments 

(Class 12 student 2023-24)


 

Young's Double Slit Experiment YDSE: Small slits made in an aluminium foil and Laser light used here to get the bright and dark fringes.

12P12 Atoms



What is Continuous Spectrum and Line Spectrum? 
What is Emission Spectrum and Absorption Spectrum? 
Click on the gas name to change to Hydrogen, Helium, Neon, Mecury and Sodium Lines
Finger Prints of Gas


Basic Mathematical Formula for Physics Numerical Solving

Which maths topics should a student study if he or she has not taken maths as one of the subject to tackle Physics problems?

I have given a small collection of basic maths topics that one has to study, who have not taken maths as one of the subjects. You may have to study with a maths teacher who is willing to teach you the basics. So that you can feel comfortable for your Physics numerical solving for your CBSE or State board exams and NEET / other entrance exams.

Mostly Algebra based problems can be tried and difficult trigonometry, log, exponential based problems can be skipped.

Remember this is just a guideline. If you do this short course around 30 hours, you may be able to overcome the fear of maths and feel confident for Physics problem solving.

11th Maths: 

Trigonometry: First two topics and exercises. 3.1, 3.2 (4 to 8 hours)

Introduction to Three Dimentional geometry: All topics and Exercises 11.1, 11.2 (4 to 8 hours)

Limits and Derivatives: Simple concepts on limits and derivatives. Solving some simple problems in Algebraic expressions is sufficient. Difficult trigonometric functions not necessary. (4 to 8 hours)

12th Maths:

Continuity and Differentiability: 5.2, 5.3, 5.7 simple problems in Second order differentiation. (4 to 8 hours)

Applications of Derivatives: Exercises 6.1, 6.2 (Maxima Minima finding important) (4 to 8 hours)

Integrals: Exercises 7.1, 7.8 (Area under the curve important) (4 to 8 hours)

Vector Algebra: Exercises 10.1, 10.2, 10.3, 10.4 (Entire chapter very important for Physics as we use dot product, cross product all the time) (4 to 8 hours)
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What? Basic Mathematical Formula for Physics Numerical Solving

Why? While doing Physics Numerical Solving students struggle with basic Maths principle that has to be applied in the numericals. Especially topics such as Vector Multiplication, Basic Differentiation, Basic Integration etc. students need help.