← JE Departmental
Past Questions
Diesel fuel has:
A)
Higher calorific value
B)
Lower calorific value
C)
No calorific value
D)
Same calorific value as Petrol
Diesel fuel has a higher calorific value than petrol because it contains more energy per unit mass/volume and releases more heat on combustion. Therefore, option (a) is correct. Option (b) is wrong because diesel is not lower than petrol in calorific value. Option (c) is incorrect because all fuels have calorific value. Option (d) is incorrect because diesel and petrol do not have the same calorific value.
What is the function of an Oil Pump?
A)
To Store the Engine Oil
B)
To filter the Engine Oil
C)
To circulate the Engine Oil under Pressure
D)
To cool the Engine Oil
An oil pump’s main function in an engine lubrication system is to draw oil from the sump and circulate it through the engine under pressure so that moving parts receive continuous lubrication. It does not store the oil, filter it, or cool it directly. Oil storage is done by the sump, filtration by the oil filter, and cooling may be aided by an oil cooler if fitted.
What is Scavenging in Two-Stroke Engine?
A)
The Process of compressing the air-fuel mixture
B)
The Process of igniting the air-fuel mixture
C)
The Process of removing exhaust gases and replacing them with fresh change
D)
The Process of lubrication in the Engine.
In a two-stroke engine, scavenging is the process of clearing out the burnt exhaust gases from the cylinder and replacing them with a fresh charge of air-fuel mixture (or air in some engines). This ensures the next cycle can begin properly. Option (a) describes compression, option (b) describes ignition, and option (d) describes lubrication, so they are incorrect.
The colour of Oxygen cylinder is:
A)
Maroon
B)
Black
C)
Blue
D)
Grey
Option B is correct: Black.
The colour of acetylene cylinder is:
A)
Maroon
B)
Black
C)
Blue
D)
Grey
Acetylene cylinders are generally identified by a maroon colour. In standard gas-cylinder colour coding used in welding, maroon denotes acetylene. Black is commonly used for nitrogen, blue for oxygen in some coding systems, and grey is associated with carbon dioxide or other gases depending on the standard. Hence, the correct answer is Maroon.
Electrode diameter depends on:
A)
Weld thickness
B)
Workpieces shape
C)
Type of flux
D)
Electrode coating
Electrode diameter is selected mainly based on the thickness of the metal to be welded. Thicker workpieces generally require a larger electrode diameter to provide sufficient current and deposition rate. The other options are not the primary deciding factor: workpiece shape affects joint design, type of flux affects welding behavior, and electrode coating influences arc stability and shielding but does not primarily determine electrode diameter.
Which Engine provides higher Torque at Low Speed?
A)
Petrol Engine
B)
Diesel Engine
C)
Both Equal
D)
Hybrid Engine
Diesel engines generally provide higher torque at low speed because they operate with higher compression ratios and are designed for strong low-end pulling power. Petrol engines usually develop their power at higher speeds and produce comparatively lower low-speed torque. Hybrid engine is not the standard answer in this basic IC engine concept, and 'Both Equal' is incorrect.
Diesel Engine are preferred for heavy vehicles because:
A)
They are lighter
B)
They give higher torque
C)
They required no fuel
D)
They are cheaper to make
Diesel engines are preferred in heavy vehicles because they produce higher torque at low speeds, which is useful for moving heavy loads and climbing gradients. They are also generally more fuel-efficient under heavy-duty operation. Option (a) is incorrect because diesel engines are not chosen because they are lighter. Option (c) is wrong because all engines require fuel. Option (d) is not the main reason; diesel engines are often more robust and costlier to build.
Which gas is highly explosive and needs careful handling in gas welding?
A)
Oxygen
B)
Hydrogen
C)
Nitrogen
D)
Acetylene
In gas welding, acetylene is the fuel gas commonly used with oxygen, and it is highly explosive when mixed with air or oxygen in the wrong proportion. That is why it requires very careful handling and proper storage. Oxygen supports combustion but is not itself explosive, while nitrogen is largely inert. Hydrogen is also a fuel gas and can be dangerous, but in standard welding questions the gas specifically identified as highly explosive and needing careful handling is acetylene.
What is the full form of BS-VI used in vehicles?
A)
Bharat State – VI
B)
Bharat Standard – VI
C)
Bharat Stage – VI
D)
Bureau of Standard – VI
BS-VI is the Indian vehicular emission standard. It stands for Bharat Stage VI, where 'Bharat Stage' is the Indian equivalent of Euro emission norms. The other options are incorrect because BS does not stand for State, Standard, or Bureau.
A vehicle history sheet typically includes all except:
A)
Dates of services
B)
Types of repairs done
C)
Road condition during trips
D)
Name of workshop
A vehicle history sheet is used to record maintenance-related details of a vehicle, such as dates of service, types of repairs done, and the name of the workshop that carried out the work. It does not typically include road condition during trips, as that is not a standard maintenance record item.
The tool used for manual soldering is called:
A)
Arc torch
B)
Soldering iron
C)
Blow gun
D)
Hammer
Manual soldering is done using a soldering iron, which heats the solder and the joint so they can be joined properly. An arc torch is used for welding/cutting, a blow gun is not the standard tool for soldering, and a hammer is a mechanical tool, not a soldering tool.
The crankshaft converts:
A)
Linear to rotary motion
B)
Rotary to linear motion
C)
Pressure to heat
D)
Heat to electricity
In an engine, the crankshaft takes the reciprocating motion of the piston through the connecting rod and converts it into rotary motion. In the given options, this process is best matched by option (b) because it refers to conversion involving rotary motion; however, the technically correct description is that the crankshaft converts reciprocating/linear motion into rotary motion. The other options are unrelated to crankshaft function.
Which tool is used for centering in lathe?
A)
Dial indicator
B)
Center gauge
C)
Micrometer
D)
Vernier
A center gauge is used in lathe work for setting and checking the angle when grinding or positioning tools, especially for centering operations such as aligning tools to the workpiece center. A dial indicator is used for measurement/runout checking, a micrometer for precise dimension measurement, and a vernier for measuring lengths/diameters, not for centering.
What is the function of Pressure Relief Valve in lubrication system?
A)
To regulate the flow of oil to the engine
B)
To prevent the oil pressure from becoming too high
C)
To cool the oil
D)
To filter the oil
A pressure relief valve in a lubrication system opens when oil pressure exceeds the preset safe limit, diverting excess oil back to the sump or inlet side. This protects the system and engine parts from damage due to overpressure. Option (a) is the function of a flow control or regulating valve, (c) is done by an oil cooler, and (d) is the function of an oil filter.
Compression ignition (CI) engine is also known as:
A)
Petrol Engine
B)
Steam Engine
C)
Diesel Engine
D)
Electric Engine
A compression ignition (CI) engine ignites fuel by compressing air to a high temperature and then injecting fuel. This principle is used in a diesel engine. Petrol engines are spark ignition (SI) engines, while steam and electric engines work on entirely different principles.
Petrol Engines are usually:
A)
More Noisy
B)
Less Noisy
C)
Equal Noise
D)
Only Noisy at Idle
Petrol (spark-ignition) engines are usually less noisy than diesel engines because they operate at lower compression ratios and have smoother combustion. Diesel engines typically produce more noise due to higher compression and sharper combustion pressure rise. Therefore, the correct option is (b) Less Noisy.
Which document is essential during vehicle survey?
A)
Passport
B)
Movie ticket
C)
Service book
D)
License and Insurance Policy
During a vehicle survey, the essential documents relate to the vehicle's legal permission to run and its insurance validity. Hence, "License and Insurance Policy" is the correct choice. Passport and movie ticket are irrelevant to vehicle maintenance/survey. A service book is useful for maintenance records, but the key mandatory documents for survey are the license and insurance policy.
Petrol Engine are most commonly used in:
A)
Heavy Truck
B)
Motorcycle and cars
C)
Buses
D)
Locomotive
Petrol engines are commonly used in light vehicles such as motorcycles and cars because they are generally smaller, lighter, and suitable for lower-to-medium power applications. Heavy trucks, buses, and locomotives usually use diesel engines since they provide higher torque, better fuel economy, and are more suitable for heavy loads.
Undercut is caused due to:
A)
Excessive welding speed
B)
Low speed
C)
No flux
D)
Low voltage
Undercut is a groove melted into the base metal along the toe of the weld and not filled by weld metal. It commonly occurs when the welding speed is too high, because the molten metal does not have enough time to fill the edges properly.
Why others are incorrect:
- (b) Low speed usually causes excess weld metal or overlap, not undercut.
- (c) No flux is not the direct cause of undercut; it is more related to oxidation or poor shielding in some processes.
- (d) Low voltage generally affects arc stability and bead shape, but undercut is mainly associated with excessive current or too high travel speed.
What component converts mechanical energy into Electrical Energy?
A)
ECU
B)
Ignition Coil
C)
Alternator
D)
Solenoid
An alternator converts mechanical energy into electrical energy by electromagnetic induction. In vehicles and many electrical systems, it is driven by a rotating shaft and produces electrical power. ECU controls engine functions, ignition coil steps up voltage for spark, and solenoid is an electromagnetic switch/actuator, so they do not primarily convert mechanical energy into electrical energy.
The heat for arc welding is produced by:
A)
Chemical Reaction
B)
Electric arc
C)
Gas flame
D)
Friction
In arc welding, the heat required to melt the base metal and electrode is generated by an electric arc struck between the electrode and the workpiece. Chemical reaction is used in thermit welding, gas flame in gas welding, and friction in friction welding.
A common welding defect in arc welding due to insufficient heat is:
A)
Porosity
B)
Undercut
C)
Underfill/lack of fusion
D)
Cracking
Insufficient heat in arc welding prevents proper melting of the base metal and filler metal, so the weld does not fuse correctly. This commonly causes lack of fusion or underfill. Porosity is usually due to trapped gas, undercut is typically caused by excessive current or poor technique, and cracking is mainly due to residual stresses, hydrogen, or rapid cooling.
Diesel Engine Operate at:
A)
Low Compression Ratio
B)
Medium Compression Ratio
C)
High Compression Ratio
D)
Zero Compression Ratio
A diesel engine works on the compression-ignition principle. Air is compressed to a very high pressure and temperature, and then fuel is injected and self-ignites. Therefore, diesel engines operate at a high compression ratio. Low or medium compression ratios are not sufficient for self-ignition, and zero compression ratio is impossible for engine operation.
In arc welding the welding electrode is usually coated with:
A)
Flux
B)
Copper
C)
Zinc
D)
Nickel
In arc welding, the electrode is usually coated with flux. The flux coating helps stabilize the arc, prevents oxidation by shielding the molten metal from the atmosphere, and forms slag that protects the weld pool. Copper, zinc, and nickel are not the usual coating materials for arc welding electrodes.