Assured science classes

https://youtu.be/_G9AlY0OdrY When a ray of light return back after striking a surface this is  called reflection of light . Laws of reflection 1-Incident ray ,reflected ray and point of incident exit in same surface . 2-Angle of incidence is equal to angle of reflection i.e  i=r . These laws of reflection are applicable to all types of reflecting surfaces including  plane and spherical surfaces . Mirror is an optical instrument by which we see or obtain image of a object .It is based on the principle of    reflection of light . Note - Opposite surface of a mirror is coated by silver and red paint .    Plane mirror that mirror whose reflecting surface is plane . Some important points related to a plane mirror 1) when an object moves with V m/s towards a plane mirror image velocity will be 2V m/s 2)The length of a plane mirror  should be  half length of a man to viewing his full image . 3)When a plane mirror rotated through thita angle ,the reflected ray moves through 2thita . 4)Number o

A data logger is a electronic storage device which gives information. Here data means information and logger means electronic storage device. It is just like a black box in railway signalling. A data logger logs the information about the relays, which are connected to the data logger or remote terminal unit. Various analog supplies can also be connected to the data logger for monitoring the voltages. Image of a data logger unit The logged information by the data logger will be processed with the help of software in order to to empowered the monitoring system. the logged data are stored in the hard disk. this information can be viewed in the text format or Graphical format.This information is helpful to the user for knowing the working functionality of the signalling system and also analyzes the faults using different kinds of reports. The main usage of data logger   in railway is for preventive maintenance of various railway equipments and detecting the causes of faults. The da

Heat  is a form of energy which gives the sensation of hotness or coldness. Temperature  is   the degree of hotness or coldness.There are different scales to measure temperature and the instrument by which temperature can measure is called THERMOMETER . Name of different temperature scales 1- centigrade 2-Fahrenheite 3- Reaumer 4 -kalvin   Symbols are   used as C is used for centigrade F is used for fahrenheite R for Reaumer K for kalvin For different scales of measurement of temperature upper fixed value as boiling point and lower fixed value as melting points are taken. In case of Celsius scale , the upper fixed  point is taken as 100 degree  and the lower fixed point is taken as zero degree centigrade. In case of fahrenheit scale these are 212 degree and 32 degree. In case of reaumer scale these are taken as 80 degree and zero degree. In case of Kelvin scale these are taken as 373 and 273. Note- All those are divided into 100 equal parts and each part is called are calle

                       Fuse is used in electric circuits as safety device . It protects circuits and appliances by stopping the flow of any unduly high electric current .  The fuse is placed in series with the device . it consists of a piece of wire made of a metal oran alloy of appropriate melting point , for example aluminium copper iron lead etc . If a current larger than the  specified value flow through the circuit , the temperature of the fuse wire increases. this melts the fuse wire and breaks the circuit. The fuse wire is usually encased in a heritage of porcelain or similar material with metal ends .  It always connecting in series and made up of metal wire having low melting point . Resistance of a wire depends on lenght of wire , it's crossectional area ,and temperature . Resistance resistance is directly proportional to length of wire and inversely proportional to area of cross section it also so that is proportion to temperature . Therefore if metal wire of

Heilights of webfil's  BPAC   Block proving by axle counter is a system used for controllingthe coordinated movement of the train in the block section working on absolute block working .The system has been developed as per IRS:105/2012 Ver.0 for signal line block working . System overview 1) Universal fail safe Block interface 2) Block panel 3) Signal section digital axle countet 4) Quad cable or voice channel on OFC 5) Battery set 6) Battery charger / ips module 7) Relay rack with relay 8) Block telefone NOTE - UFSBI AND RELAYS TO WORKS ON 24 V DC WITH MAXIMUM CURRENT CONSUPTION OF 5A Nomenclature of relays of ufsbi Image -1 image 2 image 3 Power supply and interconnection

Image of a home signal with route signal and calling on signal Signal:- A signal is that thing which convey information about a track or road on which a vehicle redy to pass Types :- On the basis of their existence and working there are mainly three types . 1- Main signal 2-subsidery signal 3- Auxiliary signal          image of a shunt signal                               (subsidery signal)         image of a advance stater                 (Main signal )     Explanation :-  For lit a main signals i.e Home ,stater ,advance stater ,inner distance ,distance ,  ibs etc . Require voltage - 90 v to 110 v a.c Require current - 130 ma  Fuse - glass fuse -630 ma For subsidary signal  SHUNT SIGNAL  ;- It is subsidary signal .It can place dependent or independent .Some signala are used as only  STOP SIGNAL . Parameter ;- Voltage -110 v ac Current - 60 ma  The name of  led of a shunt   signal are as ON ,OFF ,PIOLET  Note - The arrow marks which show on which lin

https://drive.google.com/file/d/1VaZrhb5utctqzcC84CWp6ty-0Uro2uun/view?usp=drivesdk 👉 Trigonometric raios are used to find the height and distance of aobject .   Its also uses to find the speed , time to reach a ship to a point  and also many type of angle related measurement can be found by trigonometry . Sir george everest in 1856  invented a moving telescope by which he had measured the height of the heightest  peak , and therefore the heightest peak is named as The everest .                      Thanks

what is fuse , what is pptc                    A Battery  converts chemical energy into electrical energy . A group of batteries is called is called cell . 👉 A Dry cell is that cell which has not any liquid electrolyte .                      A dry cell 👉 Lead acid cell means that secondary cell which contains lead pb as electrode and acid H2SO4 as electrolyte . It is also called voltaic cell .Volta invented it therefore on him honour its name became votaic cell . Parts of lead acid cell 1-Positive terminal post 2-Negative terminal post 3-float indicator 4-seprator 5-plate paste 6-pvc container 👉 There are three types of              Lead  acid cell .         image of a lead acid cel 1) conventional flooded lead acid battery 2) low maintenance lead acid battery (LMLA ) 3) valve regulating lead acid battery (VRLA ) Capacity of cells depend on  1)  types of cells 2)  thickness of plate  3)  construction of plate 4)  size of plate 👉 Capacity of battery is expres

Technician in                       Railway  ITI ke bad kya kare Technician  :- grade- 3  Scale: - (5200-20,200 ) Grade pay :-1900 Eligibility :-age (18-30 ) Reservation :- sc/st :-5 yearn  Obc :-3 year Pwd :-10 year Minimum qualification  For signal tech 3 :- 12 th pass with physics , math  and if not 10 th pass with iti in fiter , welder , wireman , electrician etc .              A technician image   Other for different tech -3 exam 10 th pass with iti must .                 A moving train        For alp ( assistance loco pilot ) :- 10 th plus iti must .  ITI must be approved by NCVT OR SCVT .  Here , you have to attend 2 test pre and mains for sig tech 3 . In all tech -3 number of questions  are always 100 with 1/4 negative marking  Question :- multiple choice  👉 For example :- 1-which of the following is the smallest prime number ? a) 1.                                  rrb kolcutta b) 0.                                 Tech 3 sig  c) 2 d) 3 What is your answer ? I give answer its