Posts

Magnetic Effect of Electric Current

Image
 Magnet:  (i) is an object that attracts objects made of iron, cobalt & nickel. (ii) Comes to rest in North-South direction, when suspended freely. ? Magnets are used:  (i) In radio & stereo speakers, (ii) In refrigerator doors, (iii) on audio & video cassettes players, (iv) On hard discs & floppies of computers & (v) in children's toys. ? Magnetic field:  The area around a magnet where a magnetic force is experienced is called a magnetic field. It is a quantity that has both direction & magnitude. ? Magnetic field lines:  Magnetic field is represented by field lines. They are lines drawn in a Magnetic field along which a North magnetic pole moves. Magnetic field lines are called as Magnetic lines of force. Properties of Magnetic field lines: (i) They do not intersect each other. (ii)  It is taken by convention that magnetic field lines emerge from North pole and merge at the South pole. Inside the magnet, their direction ...

Electricity

Image
1. Positive and negative charges:  The charge acquired by a glass rod when rubbed with silk is called positive charge and the charge acquired by an ebonite rod when rubbed with wool is called negative charge. 2.Coulomb:  It is the S.I. unit of charge. One coulomb is defined as that amount of charge which repels an equal and similar charge with a force of 9 x 10 9  N when placed in vacuum at a distance of 1 meter from it. Charge on an electron = -1.6 x 10 -19  coulomb. 3 Static and current electricities:  Static electricity deals with the electric charges at rest while the current electricity deals with the electric charges in motion. 4.Conductor:  A substance which allows passage of electric charges through it easily is called a ?conductor. A conductor offers very low resistance to the flow of current. For example copper,silver, aluminium etc. 5.Insulator:  A substance that has infinitely high resistance does not allow electric current to ...

XML basics

Image
XML | Basics Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable.The design goals of XML focus on simplicity,generality,and usability across the Internet.It is a textual data format with strong support via Unicode for different human languages. Although the design of XML focuses on documents, the language is widely used for the representation of arbitrary data structures such as those used in web services. XML stands for extensible Markup Language XML is a markup language like HTML XML is designed to store and transport data XML is designed to be self-descriptive Differences between XML and HTML XML and HTML were designed with different goals: XML is designed to carry data emphasizing on what type of data it is. HTML is designed to display data emphasizing on how data looks XML tags are not predefined like HTML tags. HTML is a markup language whereas ...

Trigonometry Identities

Basic and Pythagorean Identities \csc(x) = \dfrac{1}{\sin(x)} csc ( x ) = sin ( x ) 1 ​ \sin(x) = \dfrac{1}{\csc(x)} sin ( x ) = csc ( x ) 1 ​ \sec(x) = \dfrac{1}{\cos(x)} sec ( x ) = cos ( x ) 1 ​ \cos(x) = \dfrac{1}{\sec(x)} cos ( x ) = sec ( x ) 1 ​ \cot(x) = \dfrac{1}{\tan(x)} = \dfrac{\cos(x)}{\sin(x)} cot ( x ) = tan ( x ) 1 ​ = sin ( x ) cos ( x ) ​ \tan(x) = \dfrac{1}{\cot(x)} = \dfrac{\sin(x)}{\cos(x)} tan ( x ) = cot ( x ) 1 ​ = cos ( x ) sin ( x ) ​ Notice how a "co-(something)" trig ratio is always the reciprocal of some "non-co" ratio. You can use this fact to help you keep straight that cosecant goes with sine and secant goes with cosine. The following (particularly the first of the three below) are called "Pythagorean" identities. sin 2 ( t ) + cos 2 ( t ) = 1 tan 2 ( t ) + 1 = sec 2 ( t ) 1 + cot 2 ( t ) = csc 2 ( t ) Note that the three identities above all involve squaring and ...