THE ENGINEERS

TYPES OF PUMP & COMPRESSOR  1 . centrifugal pump 2 . reciprocating pump 3 . gear pump 4 . screw pump 5 .  vane pump

ELECTRICITY : is an  invisible force that can produce heat ,light , motion etc and many other physical effects the electricity energy is available in two forms (d.c) & (a.c)  (D.C) means direct current   AND (A.C)means alternating current DIRECT CURRENT (D.C) the direct current is that current which do not change direction it always flows in one direction from positive terminal  to negative terminal of the source the magnitude of the direct current may have or not have a constant value and thus direct current has constant magnitude with time its purest form of direct current  DIRECT CURRENT WAVE ALTERNATING  CURRENT  (A.C) the alternating current or voltage which changes its magnitude and direction with time regularly is known as alternating current  an alternating current can also be defined as that which changes its magnitude in one direction from   zero and then going through similar variation but in opposite direction ...

heat engine is use the converts chemical energy of (FUEL) into mechanical  energy so obtained may be used to drive an alternator to produce electricity or it may be used to drive an automobile or it may be used for any other useful purpose the chemical energy of fuel is derive from combustion of fuel heat engine are broadly classified internal combustion engine (I.C. ENGINE) ,external combustion engine (E.C ENGINE) 1.  INTERNAL COMBUSTION ENGINE (I.C ENGINE) the heat engine in which the combustion of fuel (LIQUID & GAS ) takes place inside burn inside the engine cylinder is known as internal combustion engine for ex. petrol engine diesel engine etc called I.C engine 2.  EXTERNAL COMBUSTION ENGINE (E.C ENGINE) the heat engine in which the combustion of fuel takes place outside the engine cylinder is known as external combustion engine for ex. steam engine steam turbines gas turbines etc called e.c engine  ( AJIT KUMAR)

Variable Transformers What is a Variable Transformer? A variable transformer provide a simple, rotate method of controlling electrical voltage, current and power. It takes in utility line voltage and provide continuously adjustable output voltage. When the value of the voltage on the AC line is incorrect, just a turn of the variable transformer dial operates a sliding brush that makes it right. The same dial can act like a rotate to control the speed of motors; cutting input voltage reduces the motor speed. A turn of the dial converts power line output into the desired voltage. Versatility of the variable transformer lies in its ability to tap in anywhere from 0 to 100% of the line voltage, plus another 17% usually available because of a few extra windings in the secondary. Depending on the frame size, the output current ranges from 1 to 50 A at 120 V or half this amperage at 240V. Added versatility is possible by larger size units. Some single coil variable transformers are available...

THE TERM MATERIAL SCIENCE COMPRISES TWO WORDS : MATERIALS AND SCIENCE . MATERIALS MEANS ENGINEERING MATERIALS AND THOSE ARE LIMITED TO ONLY SOLID MATERIALS . IN GENERAL THE WAORD SCIENCE DEFINES THE KNOWLEDGE ARRANGED UNDER GENERAL TRUTH AND PRINCIPLES AND IT NATURALLY COVERS TODAY A WIDE RANGE OF SUBJECTS BUT IN MATERIAL SCIENCE REFERS TO THE PHYSICAL SCIENCES RELATING TO PHYSICS AND CHEMISTRY IN MATERIAL SCIENCE SINCE WE CONFINE OUR ATENTION TO SOLID MATERIALS ONLY SO THE SUBJECT IS RELATED TO SOLID STATE PHYSICS AND SOLID STATE CHEMISTRY. IN GENERAL THE " MATERIAL SCIENCE " REFERS TO THAT BRANCH OF APPLIED SCIENCE WHICH IS CONCERNED WITH INVESTIGATING THE RELATIONSHIP EXISTING BETWEEN THE STRUCTURES  OF MATERIALS AND THEIR PROPERTIES AND THEIR INTER-DISCIPLINARY STUDY OF MATERIALS FOR PRATICAL PURPOSES ENTIRELY . (AJIT KUMAR)