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Electrictrostatics of condcutors

Conductors have a lot of electrons almost in the range of 1029 per cubic m. So, subjecting conductors to an external field usually results in the rearrangement of the electrons such that the positive ions are away from the Electric field and the negative ones closer to the electric field. This gives rise to an induced electric field that grows on strength till it becomes equal to the external field.  So, inside the conductor, the net electric field is zero.  Using this property, we can find other attributes of the electrostatics of the conductors.  The major attributes are as follows; (1) The electric field inside a conductor is zero.  (2) The external electric field will always be perpendicular to the surface of the conductor.  (3) The charge inside a conductor is zero.  (4) The potential of a conductor is constant.  (5) The electric field due to a conductor is given by E = σ/εₒ\ (6) The zero value of the electric field inside the conductor helps to h...

Potential due to dipole

 Electrostatic potential due to positive charge is q/4πεₒr and physically it requires work to bring another charge at position r to overcome the force of attraction. If unsupported the charge thus brought will be repelled and accelerated away. Similarly, for a negative charge, the potential is given by  (-q)/4πεₒr and it means that we need to prevent a positive test charge from bumping into the negative charge. If unsupported, the negative charges will be attracted and accelerated towards the negative charge.  A dipole has positive and negative charges of the same magnitude separated by a certain distance which is of the order of angstrom. At the center of the dipole, there is zero potential. The potential of a dipole is zero if the point happens to be equidistant from the positive and the negative charges. So, for a point on the perpendicular bisector, the potential is always equal to zero. However, it will be influenced by either of the charges if the point is closer to...

Chapter 2 : Electrostatic Potential and Capacitance

  Introduction: Electrostatic potential due to positive charge is q/4πεₒr and physically it requires work to bring another charge at position r to overcome the force of attraction. If unsupported the charge thus brought will be repelled and accelerated away. Similarly, for a negative charge, the potential is given by  (-q)/4πεₒr and it means that we need to prevent a positive test charge from bumping into the negative charge. If unsupported, the negative charges will be attracted and accelerated towards the negative charge.  A dipole has positive and negative charges of the same magnitude separated by a certain distance which is of the order of angstrom. At the center of the dipole, there is zero potential. The potential of a dipole is zero if the point happens to be equidistant from the positive and the negative charges. So, for a point on the perpendicular bisector, the potential is always equal to zero. However, it will be influenced by either of the charges if th...

Tips for Isometric projection of machine blocks

Orthographic projection gives us views of objects from a particular direction only. Looking from the front, we get front elevation and from the top, we get a plan or the top view. The orthographic projection is complete in one direction only. To have an entire detail, we need to prepare at least three different views from three different directions. Still, for a quick reference, a pictorial view will be a better option.  We have several ways of drawing pictorial drawings on a two-dimensional plane. It can be a perspective or oblique or isometric pictorial drawing. For Engineering Graphics, we usually use isometric projection to obtain the pictorial impression. In isometric projection, there are three principal axes inclined to each other at an angle of 120 degrees. The corresponding planes are the horizontal plane, the vertical plane, and the profile plane.  For machine blocks, we usually practice with simple cubes, prisms, and pyramids with different orientations. The sol...

Revision of Chapter 1 : Electric Charges and Fields Revision

 

CBSE Class 12 Term 2 Sample Paper 1 Marking Scheme

 

Grade 12 Chapter 2 : Electrostatic Potential and Capacitance

 Chapter 2: Electrostatic Potential and Capacitance.  Starting from the concept of electrical work, we establish the concept of electrostatic potential energy. This energy per unit charge is defined as the electric potential. We obtain an expression for the potential of a source charge by bringing a unit test charge from infinity to a location in the space. Similarly, using the geometry, we can find the potential due to the dipole.  Moreover, we can relate the electric field and the potential also. Usually, the electric field is taken as the negative of the potential gradient.  To create a system of charges, we have to spend some energy and this will be stored as the potential energy of the system. The same logic can be extended for rotating a dipole in an external field. Here also, by doing work against the net torque of the uniform external field, we can store the energy in the dipole.  A very interesting point of discussion in Chapter 2 is related to the elec...

CBSE Class 12 Term 2 Sample Paper 1

 

Isometric Scale

 An isometric scale is used for isometric projection. Most of the drawings on a plain sheet of paper are 2-dimensional. We can use three axes at 120o with each other to indicate three dimensions of an object. This generally helps in creating 3-dimensional drawings on a 2D plane.  CBSE Class 12 has isometric scale construction as an essential construction skill.  The steps of construction are as follows; (1) Draw a horizontal line.  (2) Draw an inclined line at 45o with east which is the default 0o.  (3) Using your roller, divide the given true length on the inclined line. If you have to draw an isometric scale of 70 mm, then draw the line of up to 80.  (4) Keep the first 1 cm for dividing into 10 equal parts of  1 mm. Thereafter, divide the length into the required number of equal parts.  (5) Draw another line at 30; with default east.  (6) Draw a vertical line at 30.  (5) Take the height of the line as 4 mm and complete the scale. ...

Grade 12 Chapter 1 Assignment 1

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Sketchup Videos

 YouTube has a trove of videos for free learning of CAD. Recently, Google SketchUp has caught up with designers and creators due to its ease of use. If you are interested, you can find the following video worthwhile. 

Engineering Graphics

CBSE Curriculum of Engineering Graphics is designed to create lifelong learners with sharp thinking skills. Especially the creators of different spheres find the nuances elucidated in this subject very enriching.  CBSE has outlined the following objectives for this course: Objectives: The study of the subject of Engineering Graphics at the Senior School Level aims at helping the learner to:  develop clear concepts and perceptions of different objects.  develop a clear understanding of plane geometry, solid geometry, and machine drawing so as to apply the same in relevant practical fields such as technology and industry.  develop the skill of expressing two-dimensional and three-dimensional objects in professional language and vice versa.  acquire speed and accuracy in the use of drawing instruments.  acquire the ability to readily draw neat sketches, often needed in "On-job situations".  use technology (CAD) in developing isometric and orthographic pro...

Grade 11 Chapter 1 : Physical World

This chapter is related to the domain, scope, focus, and properties of the physical world. The students can understand the nuances of Physics very well as some of the anecdotes have already been covered in different topics of Physics and Chemistry in grades 9 and 10. You can find the following Youtube video very useful which I have prepared for the Class of 2024. 

Grade 12 Chapter 1 : Electric Charges and Fields

 

Grade 12 Engineering Graphics Syllabus

 

Grade 11 - Engineering Graphics Syllabus

 

Grade 12 Physics Syllabus

CBSE has not updated/published the syllabus for 2022-2023. For the time being, we will continue with the last year's syllabus. The syllabus is as follows for Term 1 and Term 2; 

Grade 11 Physics Syllabus

CBSE has not updated/published the syllabus for 2022-2023. For the time being, we will continue with the last year's syllabus. The syllabus is as follows for Term 1 and Term 2; 

Grade 9 Syllabus

CBSE has not updated/published the syllabus for 2022-2023. For the time being, we will continue with the last year's syllabus.   The syllabus is as follows; The termwise breakdown is as shown below; TERM – I Unit III: Motion, Force, and Work Chapter – 8 Motion Motion: Distance and displacement, velocity; uniform and non-uniform motion along a straight line; acceleration, distance-time, and velocity-time graphs for uniform motion and uniformly accelerated motion, derivation of equations of motion by graphical method; elementary idea of uniform circular motion. Chapter – 9 Force and Laws of Motion Force and Newton’s laws: Force and Motion, Newton’s Laws of Motion, Action and Reaction forces, Inertia of a body, Inertia, and mass, Momentum, Force and Acceleration. Elementary idea of conservation of Momentum. TERM - II Unit III: Motion, Force, and Work Chapter – 10 Gravitation Gravitation: Gravitation; Universal Law of Gravitation, Force of Gravitation of the e...

Grade 10 Syllabus

CBSE has not updated/published the syllabus for 2022-2023. For the time being, we will continue with the last year's syllabus.   The syllabus is as follows; The termwise breakdown is as shown below; TERM - I Unit III: Natural Phenomena Chapter – 10 Light –Reflection and Refraction: Reflection of light by curved surfaces; Images formed by spherical mirrors, center of curvature, principal axis, principal focus, focal length, mirror formula (Derivation not required), magnification. Refraction; Laws of refraction, refractive index. Refraction of light by the spherical lens; Image formed by spherical lenses; Lens formula (Derivation not required); Magnification. Power of a lens. Chapter – 11 Human eye and colorful world Refraction of light through a prism, dispersion of light, scattering of light, applications in daily life. TERM – II Unit IV: Effects of Current Chapter – 12 Electricity Ohm’s law: Resistance, Resistivity, Factors on which the resistance of a conductor depends. S...