about Skip to main content

about

This blog knowledge world is all about information like festivals, education, online marketing, social media, environmental protection, online earnings, examination information, history, science, health, fitness, cooking etc. I hope you like all the articles on this blog, if you like information about any topic you can add your comments on the comment section, we will try to post an article for you.
contact us: knwrld2018@gmail.com

Popular posts from this blog

Thermistor-To determine the values of energy gap, Eg-limiting value of the resistance Ro

Aim: 1 . To determine the values of the energy gap E g , for a given thermistor for two different values of current passing through it.  2.   To determine the limiting value of the resistance R o. thermistor Conventional carbon and wire wound resistances have very less effect of temperature on their values of resistance. There is about 0.4  %  change in the resistance value per degree change in the temperature. They are also linear i.e. they obey Ohm’s law. However, there is a class of resistances which are temperature sensitive and show a significant change in their resistance values with temperature. Such resistances are called thermistors. A change of about 6% to 8 % in their resistance values is observed with change in temperature. They are non-linear resistances. Thermisters are used as current limiters, temperature sensors, self-resetting overcurrent protectors and self-regulating elements.  The first NTC thermistor was discovered in 1833 by Mich...
2 comments
Read more

Thomson method-To determine the value of e/m of electron using the bar magnet method.

AIM:  To determine the value of e/m of electron using the bar magnet method. To determine the value of e/m of  electron  using the bar magnet method.   J.J. Thomson, the discoverer of the electron, first determined in 1897 the ratio of the charge  e  of the electron to its mass  m  by applying electric and magnetic fields to a narrow beam of cathode rays. A Cathode Ray Tube (CRT) is a convenient device for determining e/m ratio of the electron. A narrow electron beam is produced in it and the beam can be manipulated by impressed electrical and magnetic fields over a small length of the electron path. The electric field produced by a short length of deflection plates and the magnetic field is applied from outside over the same length. APPARATUS:  A cathode ray tube (CRT), a power supply, two bar magnets, deflection magnetometer, and wooden frame with scales fixed on its arms. FORMULA        ...
11 comments
Read more

Cathode ray oscilloscope (CRO) for voltage (AC AND DC)

AIM: 1. Use of cathode ray oscilloscope (CRO) for voltage (AC AND DC) and frequency measurement (direct method)  2. To determine the frequency of unknown source using Lissajous pattern.                                             Cathode Ray Oscilloscope (CRO)           Cathode Ray Oscilloscope (CRO) is a versatile measuring instrument. The electrical parameters associated with ac signals such as voltage, current, frequency, phase etc. can be most conveniently measured using CRO. It not only measures these parameters but also displays the nature of the applied signal. (Analogue and digital meters are incapable of displaying the nature of the applied  signal.  Moreover , these meters do not measure peak value but they measure  RMS  values). Apart from the use of CRO for direct measurements ...
10 comments
Read more