Assured science classes

Relay :-Relay is a electromagnetic switch which extends ac or dc supply by picking up or dropping of its  contacts for more than one electric circuits . Types : - According to its size it has two types  1- Shelf type 2- Plug in type  A shelf type relay is very big in size  .But a plug in type relay is so small therefore now plug in type relay is used .         Self type relay and its parts                              Plug in type relay Here in the circle , written about specification ie style qn1 means q series neutral relay which does'nt use in out yard in RE area because it is not a A.C IMMUNIZED RELAY .  FOR EXAMPLE -QNA1 HERE A MEANS AC IMMUNIZED . Here ,written coil resistance of solenoide . Here , R 1 and R2 are used for energiging of relay it is its pick up voltage .here in this relay it is 24 volt d.c . Except of under square :-  All contacts are front in case of 12f /4b relay but Under square   all are back contacts .

Core of cable having different colors Different colours of core are used to counting the cores of a cable . During wiring it is very important to  connect same feed to same core of cable for running a circuit in jb i.e juction box where cable  cores are terminated . The numbering starts always from blue and it may be end at red . There are many layers of cores of a cabel depend on types of a cable ,either it is 30 core cabel ,24 core cable  ,19 core cable or any other  types of cable . In this figure  cable cores are terminated in bagho . There are different types of cables as 30 core ,24 core ,19 core ,12 core ,6 core and 2core . Uses :-   Cables  are widely used in railway signalling It also used in electrical and telecome department for electric wiring  For  telecome communication network generally quad cable or ofc are used . This is the image of a 6 quad cable . In every quad there are four core .It filled with jelly for stoping of water entering in side the cable . cable

👉 A colour coded resistor  COLOUR CODED RESISTOR   is a type of carbon resistance . There are some coloured circular colour band on its body by which we identify its value in OHM  This type of resistor is used in  Different type of electronic circuits , amplifier etc The process by which we can identify its value depends on code of different colours , its multiplier , and its tolerance value which  are given below         Name    number  multipler   T 1-Black              0             10^0     (+/- ) 2-Brown           1             10^1 3-Red                2             10^2 4-Orange           3             10^3 5-Yellow          4             10^4 6-Green           5             10^5 7-Blue              6              10^6 8-Violet           7             10^7 9-Grey             8             10^8 10-White        9             10^9 11-Golden                                   5 % 12-Silver                                    10 % 13-No colour