The reflectivity depends upon
Geometry of the reflector
Energy of neutrons
Properties of the reflector
All of these
Correct Answer :
D. All of these
Related Questions
In a four stroke cycle diesel engine, the exhaust valve
Opens at 30° before bottom dead centre and closes at 10° after top dead centre
Opens at 30° after bottom dead centre and closes at 10° before top dead centre
Opens at bottom dead centre and closes at top dead centre
May open and close anywhere
The advancing of spark timing in spark ignition engines will _________ knocking tendency.
Increase
Reduce
Not effect
None of these
The self ignition temperature of petrol is ________ as compared to diesel oil.
Same
Lower
Higher
None of these
All heat engines utilize
Low heat value of oil
High heat value of oil
Net calorific value of oil
Calorific value of fuel
The expansion of fuel in a four stroke cycle diesel engine
Starts at 15° before top dead centre and ends at 30° after top dead centre
Starts at top dead centre and ends at 30° after top dead centre
Starts at 15° after top dead centre and ends at 30° before bottom dead centre
May start and end anywhere
Which of the following statement is wrong?
A four stroke cycle engine develops twice the power as that of a two stroke cycle engine
For the same power developed, a four stroke cycle engine is lighter, less bulky and occupies less floor area
The petrol engines are costly than diesel engines
All of the above
Fuel oil consumption guarantees for I .C. engine are usually based on
Low heat value of oil
High heat value of oil
Net calorific value of oil
Calorific value of fuel
Which of the following does not relate to a spark ignition engine?
Ignition coil
Spark plug
Carburettor
Fuel injector
Antiknock for compression ignition engines is
Napthene
Tetra ethyl lead
Amyl nitrate
Hexadecane
The thermal efficiency of petrol and gas engines is about
15 %
30 %
50 %
70 %
Pick up the false statement
Thermal efficiency of diesel engine is about 34%
Theoretically correct mixture of air and petrol is approximately 15:1
High speed compression engines operate on dual combustion cycle
S.I. engines are quality governed engines
Most high speed compression engines operate on
Otto cycle
Diesel cycle
Dual cycle
Carnot cycle
The knocking in diesel engines may be prevented by
Reducing the delay period
Raising the compression ratio
Increasing the inlet pressure of air
All of these
Which of the following statement is correct regarding normal cetane?
It is a standard fuel used for knock rating of diesel engines
Its chemical name is normal hexadecane
It has long carbon chain structure
All of the above
The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called
Net efficiency
Efficiency ratio
Relative efficiency
Overall efficiency
In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as
Scavenging
Detonation
Supercharging
Polymerisation
The cetane (C16H34) which is a straight chain paraffin, is assigned a cetane number of
0
50
100
120
The working pressure and temperature inside the cylinder of an internal combustion engine is _________ as compared to a steam engine.
Low
Very low
High
Very high
In a four stroke cycle petrol engine, the pressure inside the engine cylinder during the suction stroke is __________ the atmospheric pressure.
Equal to
Below
Above
None of these
In the opposed piston diesel engine, the combustion chamber is located
Above the piston
Below the piston
Between the pistons
There is no such criterion
The specific fuel consumption per BH hour for a petrol engine is approximately
0.15 kg
0.2 kg
0.25 kg
0.3 kg
The exhaust valve in a four stroke cycle petrol engine
Opens at 50° before bottom dead centre and closes at 15° after top dead centre
Opens at bottom dead centre and closes at top dead centre
Opens at 50° after bottom dead centre and closes at 15° before top dead centre
May open and close anywhere
Which of the following medium is compressed in a Diesel engine cylinder?
Air alone
Air and fuel
Air and lub oil
Fuel alone
A 75 cc engine has following parameter as 75 cc
Fuel tank capacity
Lube oil capacity
Swept volume
Cylinder volume
In a four stroke cycle petrol engine, the expansion
Starts at top dead centre and ends at bottom dead centre
Starts at 30° before top dead centre and ends at 50° before bottom dead centre
Starts at 30° after top dead centre and ends at 50° after bottom dead centre
May start and end anywhere
The operation of forcing additional air under pressure into the engine cylinder is known as
Supercharging
Carburetion
Turbulence
Delay period
The cetane number of diesel oil, generally available, is
20 to 25
25 to 30
30 to 40
40 to 55
Theoretically, a four stroke cycle engine should develop _________ power as that of a two stroke cycle engine.
Half
Same
Double
Four times
Morse test is used to determine the I.P. of a
Single cylinder petrol engine
Four stroke engine
Single cylinder diesel engine
Multi cylinder engine
The specific fuel consumption per B.P. hour for a petrol engine is about
0.2 kg
0.25 kg
0.3 kg
0.35 kg