Advantages of MPFI system

MPFI state as a multi-point fuel injection system. The main function of the MPFI system is to supply a proper ratio of gasoline and air to the cylinders. Let us have a deep insight into the advantages of this system in this article.

Advantages of the MPFI system :

• MPFI improved fuel consumption.
• Mileage will be improved.
• ECM technique is used to control the engine.
• Precise supply of air-fuel mixture.
• The engine response is also good in the condition of the throttle applied.
• The MPFI engines vibrate less and don’t require to be cranked twice or thrice in cold weather.
• It helps in uniform combustion of fuel inside the combustion chamber.
• The exact and uniform quantity of the air-fuel mixture is provided for each cylinder.
• Cleaner emissions.
• MPFI improves the functionality and durability of the engine components.
• The mileage of the vehicle is improved. 

Working priciple of MPFI

• The MPFI is an advanced version of the carburettor engine. MPFI full meaning is a multi-point fuel injection system.
• Even though the working of MPFI engine is somewhat similar to the engine used by carburettor each cylinder is treated individually. 
• A separate injector supplies the correct quantity of fuel to each of the engine cylinders by a fuel-rail according to the firing order or in a particular sequence. This system provides further precision by varying the fuel quantity and injection timing by governing each injector separately and thereby improving the performance and controlling the emissions.
• The return valve returns fuel in case the fuel is oversupplied. Also, the pressure regulator regulates the pressure of the intake of  fuel. Fuel filter contains small-sized membranes which filter and absorbs undesirable matters of size 30 to 40 microns.
• The fuel and air are mixed in the intake manifold and each manifold is controlled by an ECU(Electronic Control Unit). fuel pressure runs between 3 to 5 bars.

Working Principle of ABS

Working principle of ABS ( Anti-lock Braking system ) :  

ABS full form is anti-lock braking system. It is very useful safety system of automobile. Now we can check it out the working principle of ABS.

• When the brakes are applied fluid is forced from the master cylinder to the HCU inlet ports with the help of open solenoid valves that are contained in the HCU, then through the outlet ports of HCU to the each wheel.
• The rear part of the master cylinder feeds the front brakes and vice-versa.
• After the fluid in inserted in each wheel, the wheel starts locking-up.
• When the control module senses that wheel is going to lock up, it closes the normally open solenoid valves for that wheel.
• The anti-lock break control module then looks at anti-lock break sensor signal from the affected wheel.
• Once the affected wheel comes back up to the speed, then the control module returns the solenoid valve to there normal condition.

Full Form of Automobile terms

4WD - Four Wheel Drive

2WD - Two Wheel Drive

AWD - All Wheel Drive

A/F - Air Fuel Ratio 

ACM - Airbag Control Module 

ACC - Automatic Climate Control OR Adaptive Cruise Control

AAT - Ambient Air Temperature 

ARAI - Automotive Research Association of India 

ABS - Anti Lock Braking System

ASFS - Advanced Swirl Flow Induction System

ATFT - Advance Tumble Flow Technology 

APDVi - Advance Pro Digital Variable Ignition System

BHP - Brake Horse Power

BMEP - Brake Mean Effective Pressure

BSFC - Brake Specific Fuel Consumption

BDC - Bottom Dead Centre

CRDi - Common Rail Direct Injection

CV - Calorific Value of the fuel

CVTI  - Charged motion Variable Time Ignition

CCVTI - Controlled Combustion Variable Timing Ignition

CC - Cubic Capacity

CDI - Capacitor Discharge Ignition

C.I ENGINE - Compression Ignition Engine

CNG - Compressed Natural Gas

DTS-i - Digital Twin Spark Ignition

DOHC - Double Overhead Camshaft

DI ENGINE - Direct Injection Engine

DFI - Digital Fuel Injection

DDIS - Direct Diesel Injection System 

EBD - Electronic Brakeforce Distribution

EFI - Electronic Fuel Injection

EC ENGINE - External Combustion Engine

ESC - Electronic Stability Control

ECU - Electronic Control Unit 

EGR - Exhaust Gas Recirculation 

EVRV - Electronic Vacuum Regulator Valve

FPEG - Free Piston Engine Generator

FHP - Frictional Horse Power

FWD - Front Wheel Drive 

GVW - Gross Vehicle Weight

HCV - Heavy Commercial Vehicle

HVAC - Heating ventilating and AirConditioning

IC ENGINE - Internal Combustion Engine

IHP - Indicated Horse Power

IMEP - Indicated Mean Effective Pressure

ISFC - Indicated Specific Fuel Consumption

Kph - Kilometer Per Hour

Kpl - Kilometer Per Liter

LCV - Light Commercial Vehicle

LSPV - Load Sensing Proportioning Valve

MPFI - Multi-point fuel injection

MUV - Multi Utility Vehicle

OHV - Over Head Valve

OBD - On Board Diagnose

PGMFI - Programmed Fuel Injection System 

PDI - Pre-delivery Inspection

RTR - Racing Throttle Response

SOHC - Single Overhead Camshaft

SUV - Sport Utility Vehicle

SAE - Society of Automotive Engineers

SFC - Specific Fuel Consumption

SI ENGINE - Spark Ignition Engine

SRS Airbag - Supplemental Restraint System Airbag

TC - Traction Control

TDi - Turbocharged Direct Ignition

TCI - Transistorized Coil Ignition

TDC - Top Dead Centre

TWI - Tread Wear Indicator 

VDB - Ventilated Disc Brake

VCR - Variable Compression Ratio  

VGT - Variable Geometry Turbocharger

VVTi - Variable Valve Timing

VTVT - Variable Timing Valve Train

WGT - Waste Gas Turbocharger 

Types of friction

The frictional force is that force responsible for wear and tear of two bodies. 

When two bodies in contact, move relative to each other then there exists a force which has a tendency to oppose that movement which is called frictional force. 

Friction plays an important part in many everyday processes. For instance, when two objects rub together, the friction causes some of the energy of motion to be converted into heat. This is why rubbing two sticks together will eventually produce a fire.

Friction is also responsible for the wear and tear on bike gears and other mechanical parts. That's why lubricants, or liquids, are often used to reduce the friction and wear and tear between moving parts. 

 There are in general  4 different types of friction.

1. Static Friction
2. Kinetic Friction
3. Rolling Friction
4. Fluid Friction

Static Friction :

• When a force is applied to an object but it does not cause it to move

Static friction comes into play when a body is forced to move along a surface but the movement does not start. 
This is the maximum force that must be overcome before a body will just start to move over another body. 
The magnitude of static friction remains equal to the applied external force and the direction is always opposite to the direction of motion. 
The magnitude of static friction depends upon μs (coefficient of static friction) and N (net normal reaction of the body).
 Example: Pushing on a wall

Kinetic Friction :

• Occurs when solid surface sliding over each other

 Kinetic friction denoted as μk comes into play when a body just starts moving along a surface. When the externally applied force is sufficient to move a body along a surface then the force which opposes this motion is called as kinetic frictional force.

This is the maximum force that must be overcome before a body will just be in uniform motion over another body.                                  

Magnitude of kinetic frictional force f_k = μk N

Where μk is coefficient of kinetic frictional force and N is the net normal reaction on the body. The magnitude of kinetic frictional force is always less than magnitude of static frictional force. When value of applied net external force F is more than f_k then body moves with a net acceleration and when these forces are equal then body moves with a constant velocity.

Example : Falling on the pavement

Rolling Friction :

•  Occurs when an object rolls over another 

Rolling frictional force is a force that slows down the motion of a rolling object. Basically it is a combination of various types of frictional forces at point of contact of wheel and ground or surface.When a hard object moves along a hard surface then static and molecular friction force retards its motion. When soft object moves over a hard surface then its distortion makes it slow down. 

Example: Riding a motorcycle, Skateboard 

Fluid Friction :

• Occurs when a object moves through a fluid 

When a body moves in a fluid or in air then there exists a resistive force which slows down the motion of the body, known as fluid frictional force. A freely falling skydiver feels a drag force due to air which acts in the upward direction or in a direction opposite to skydiver’s motion. The magnitude of this drag force increases with increment in the downward velocity of skydiver. At a particular point of time the value of this drag force becomes equal to the driving force and skydiver falls with a constant velocity.

Example : Skydiving, Swimming 

 

Difference between V Engine and Inline Engine

The pistons and cylinders are aligned in a V shape in V type engine whereas they all are vertical or inline with each other in case of the inline engine. Now, let us check it out some key point to understand the comparison and then let us have a deep insight into the difference between the V engine and inline engine. 

A key point of V-engine : 

• It is unbalanced because there is an odd number of cylinders in each bank so by its inherent design.
• Its application in rear-wheel-drive configurations is few since the space between the ends of the engine width is so big.
• Due to its compact design, The engine is very short and suitable for a lot of front-wheel-drive cars especially when power demands increase but engine sizes decrease.
• The V engine will be different angles but the common angles are 45, 60 and 90 degrees.
• If viewed from the front will resemble a V as the pistons are not vertical, they are a slant on either side of the engine.

A key point of inline engine :

• Naturally balanced, to maintain it, you only need proper tuning and the correct firing order.
• Its application in the from-wheel-drive configuration is few since space can pose a problem for engine fitment. 
• The inline engine produces more torque than V configurations and thus see its application in trucks and off-road vehicles    
• An inline 6 will be cheaper to build than a V engine.
• An inline engine can easily accommodate an odd number of cylinders like 5 cylinder engine or the 3 cylinders engine which can be used in small fuel-efficient models.
• The inline is cheaper to produce because of its straightforward design.

Difference :  

• V engines are not as efficient as the same size inline. 
• V engine more complex and usually harder to repair than an inline engine. 
• An inline engine is long and narrow mounted transversely in small car allow a very short hood whereas V engine is compact. 
• The inline configuration is sometimes more difficult to cool in an air-cooled engine as compared to V engine.
• An inline engine is wide and flat gives it a low centre of gravity.
• The inline shape needs only half as many camshafts as a V configuration (if using overhead cams), which can lighten things slightly. 
• There may also be cost differences between V engine and inline engine during manufacturing.
• V engine subjected to more vibration than an inline engine. 

Difference between conventional and non conventional machining

Conventional machining can be defined as a process using mechanical energy while other forms of energy such as thermal, chemical and electrical energy are used by non-conventional machining. Each machining process has different capabilities and suitable for a specific purpose. Now, let us have a deep insight into the difference between those two machining process. 

Difference between conventional and non-conventional machining : 

• Non-conventional tools are more precise and accurate than conventional tools.
• Machining is generally done by chip formation while material removal occurs with chip formation or even no chip formation in non-conventional machining. Example - AJM. 
• Conventional machining process involved tool wearing as there is physical contact between the tool and the workpiece while this is not the case in non-conventional machining. 
• No noise pollution is created as a result of non-conventional methods as these tools are much quieter.
• Tool life is long for non-conventional processing as compared to conventional machining. 
• Non-conventional tools are very expensive than conventional tools.
• Non-conventional tools have complex setup and hence requires a skilful operation by expert workers, whereas conventional tools do not require any special expert for its operation and are quite simple in the set-up.
• Easily available replacement parts of conventional machines but not for non-conventional machines.
• Non-conventional machines can handle very complex jobs as compared to conventional machining.
• Lower accuracy and surface finish obtained in conventional machining wherein non-conventional machining Higher accuracy and surface finish  are obtained
• With the use of conventional machining cannot produce prototype parts very efficiently and economically whereby the use of conventional machining produces parts effectively and economically.
• High waste of material due to high wear in conventional machining whereas no waster of material due to no wear in non-traditional machining. 
• Conventional machining capital cost is lower as compared with non-conventional machining. 

What is the age limit for GATE ?

• There is no any limitation of age for GATE exam

However, if you are  looking to join a PSU through GATE score, then you must fulfill their  criterion. In mostly all PSUs, the maximum age is around 26-28 years.  But, for M.Tech. admission in any institutions, there is no any age  limitation.

Checklist for filling up GATE Application form

Checklist for filling up GATE Application Form :

• Personal Details as per the certificates to be uploaded.
• Address for Communication (including PIN code),
• Academic Qualifications – College and degree
• GATE paper, GATE 2017 examination cities,
• Details of Valid Photo ID
• Photograph as specified
• Signature as specified
• Scanned copy of Degree Certificate or Certificate from Principal/HODs in pdf format.
• Scanned copy of Category/PwD Certificate (if applicable) in pdf format.

Photograph:

• Candidates must take a colour photograph in a white or very light background in a professional studio and upload it along with the GATE 2017 application form.
• The photograph must be taken after August 1, 2016, and should show the face of the candidates occupying about 50% of the area in the photograph looking into the camera directly.
• The main features of the candidate’s face must not be covered by hair of the head, any cloth or any shadow and the forehead, eyes, nose and chin should be clearly visible in the photograph.
• Candidates with spectacles must ensure that there is no glare on the glasses. Such candidates can upload a photo without glasses too.
• Only clear glasses are permitted and photos with goggle, sunglasses or tinted glasses will not be accepted.
• Mobile photos are not permitted and will be rejected.
• The photograph must be in JPEG format in a standard 3.5 cm (Width) × 4.5 cm (Height) print
• The maximum pixel resolution must be 480 × 640 (0.3 Megapixels) while the minimum pixel resolution 240 × 320.

Signature:

• A rectangular box of size 2 cm (height) × 7 cm (Width) must be drawn on an A4 white paper.
• Candidates must put their signature in black or dark blue ink within this box.
• The signature must be digitally image scanned by a professional using a scanner and cropped to the box professionally.
• The file must be in JPEG image format with a maximum pixel resolution for the image of 160 × 560 pixels and a minimum pixel resolution of 80 × 280.
• Mobile photos are not permitted.
• Signature should NOT be in Capital letters or in any ink other than Black or Blue.

Thumb Impression:

• Candidates must draw a rectangular box of size 3 cm × 5 cm (Height x Width) on an A4 white paper.
• They must mark their Left thumb impression within this box using a blue or black stamp pad.
• Candidates may upload their Right thumb impression if it is difficult to access the left thumb for any reason.
• For candidates unable to provide thumb impression for any reason, an impression of any finger will be allowed
• The signature must be digitally image scanned by a professional using a scanner and cropped to the box professionally.
• The file must be in JPEG image format with a maximum pixel resolution for the image of 160 × 560 pixels and a minimum pixel resolution of 80 × 280.
• Mobile photos are not permitted.

Photo ID Card: Candidates must keep any one of the following ready to fill the details

• Driving License,
• Passport, PAN Card,
• Voter ID,
• Aadhaar UID,
• College ID,
• Employee Identification Card,
• Notarized Affidavit with Photo, Signature, Date of Birth and Residential Address
• International Students must enter details of their passport only.

For Candidates in their final year:

• A copy of the Marks Sheet of the previous semester/year or mark sheet for section A of AMIE in case of professional equivalent qualifications.
• This must be in pdf format only

Degree Certificate/Provisional Certificate/Course Completion Certificate:

• Candidates who have completed their qualifying degree must upload this.
• The file must be in PDF format only

Caste Certificate if applicable: 

This is in PDF format only

Disability Certificate if applicable: 

This is in PDF format only

What is fee for GATE Exam

GATE Exam Application Fee :

• Male (General/OBC) and other : 1500 INR
• SC/ST/PWD Candidates and Woman (All Categories) : 750 INR
• International Students : US Dollars 50

You will have to pay money online by Selecting any recommended methods. Available options for GATE online payments are Debit card Payment, Credit Card, Using Netbanking or Using E-Challan. Some additional charges will also be placed by the banks for charges (if applicable).

After successful payment, a unique “Fee Payment Number” will be generated which must be saved by the candidate. 

Note: Candidates who belong to SC or ST or PwD category have to upload a valid documentary evidence for concession in fees.