Question Discussion & Solution

The correct answer is Ethyl mercaptan.

Key Points

• The stench due to leakage from the LPG cylinder because of Ethyl mercaptan.
  • LPG gas is basically propane and butane.
  • It is odourless in its natural state.
  • The smell that you notice when there is a leak is actually the stench of an entirely different agent, called ethyl mercaptan​.
    • This substance is added to the gas when it leaves the main storage terminals.
• Hence, option 4 is correct.

Additional Information

• Methane :
  • Methane is a chemical compound with the chemical formula CH₄.
  • Methane is a one-carbon compound in which the carbon is attached by single bonds to four hydrogen atoms
  • It is a group-14 hydride and the simplest alkane and is the main constituent of natural gas.
  • It is a colourless, odourless, non-toxic but flammable gas.
  • It has a role as a fossil fuel, a member of greenhouse gas, and a bacterial metabolite.
• Butane :
  • Butane or n-butane is an alkane with the formula C₄H₁₀.
  • Butane is a gas at room temperature and atmospheric pressure.
  • Butane is a highly flammable, colourless, easily liquefied gas that quickly vaporizes at room temperature.
  • Butane is a hydrocarbon and a highly flammable, colourless, odourless, easily liquefied gas.
  • It is typically used as fuel for cigarette lighters and portable stoves, a propellant in aerosols, a heating fuel, a refrigerant.
• Propane :
  • Propane is a three-carbon alkane with the molecular formula C₃H₈.
  • It is a gas at standard temperature and pressure, but compressible to a transportable liquid. 
  • Propane is a flammable hydrocarbon gas that is liquefied through pressurization and commonly used for fuel in heating, cooling, hot water, and vehicles.
  • Propane can also be used for refrigerants, aerosol propellants, and petrochemical feedstock.​ 

The pattern is:

15

15 × 3 - 3 = 42;

42 × 4 - 4 = 164

164 × 5 - 5 = 815;

815 × 6 - 6 = 4884

Explanation:

• Dynamite is an explosive which is used in mining, quarrying, construction and demolition industries. 
• It is made of Nitroglycerin, sorbents and stabilizers. 
• It was invented by Swedish Chemist Sir Alfred Nobel on whose memory the Nobel Prize has been constituted. 
• Nitro Glycerin: C3H5N3O9

Concept:

Pure virtual function:

• A pure virtual function is a virtual function that is required to be implemented by a derived class if derived class is not abstract.
• Base class containing pure virtual function becomes abstract.

Syntax of pure virtual function:

Virtual func_type func_name () = 0;

So option 4 is the correct answer.

 The correct answer is Electrically Erasable Programmable Read-Only Memory.

Key Points

• EEPROM stands for Electrically Erasable Programmable Read-Only Memory.
• It is a non-volatile memory in which the information stored Is retained even after the power goes off.
• A special type of PROM in which the information stored in it can be erased by exposing it to an electrical charge at one byte at a time. 
• EEPROM generally offers excellent capabilities and performance.
• EEPROMs are constructed as arrays of floating-gate transistors.