Question Discussion & Solution

Concept:

• The laws dealing with ideal gases naturally called ideal gas laws, and the laws determined in the seventeenth century by Boyle's observational work and in the eighteenth century by Charles.
• The Boyles Law states that the gas pressure is inversely proportional to the gas volume for a given mass of gas stored at a constant temperature.
• Charles Law states that the gas volume is directly proportional to the gas temperature for a given fixed mass of gas stored at a constant pressure. 
• An ideal gas is a gas that follows the equation:

PV = nRT at all temperatures and pressure, where P = Pressure of the ideal gas. V = Volume of the ideal gas n = Amount of ideal gas measured in terms of moles 

R = Universal gas constant T = Temperature

Mole Concept -

•  The quantity one mole of a substance signifies 6.022 × 1023 number of particles of that substance which may be atoms, molecules, or ions.
• The quantity is a universal constant like Dozen, Gross, etc., and is known as Avogadro number, denoted by NA. after the scientist Amedeo Avogadro.
• Examples- In one mole of H2, there are 6.022 × 1023 molecules of hydrogen, and the number of atoms is 2 × 6.022 × 1023, as one molecule of hydrogen contains two-atom each.
• The mass of one mole of a substance is called its Molar Mass (M) or Atomic mass expressed in grams.
• The volume occupied by a mole of gas is 22.4 L at NTP, called its Molar Volume.
• The no. of moles (n) is calculated as =

The number of particles / Avogadro’s number.

To summarise, we can say, 

Calculation:

• The molar mass of 1 mole of H₂SO₄ is =

2 × 1 + 32 + 4 × 16 = 98g

• The molar mass of 1 mole of Silver, Ag is its molecular mass 108g.
• The molar mass of CO₂ is = 12 + 2× 16 = 44g.
• 44g of CO₂ means one mole.
• 1 mole of Oxygen weighs 16 + 16 = 32g.
• Hence, the highest mass is of 1 mole of Ag.

Given:

The only one figure that satisfies the given pattern is: 

Hence, A is the correct answer.

It is not always necessary that we need a movie and an actor for a song. A song can be created without them. Microphone is also not essential for a song but lyrics are an essential part of a song as lyrics are the words that actually make up a song. Without, lyrics a song cannot be written.

The correct answer is Dot Matrix.

Important Points

• Impact printer
  • Impact printer refers to a class of printers that work by banging a head or needle against an ink ribbon to make a mark on the paper.
  • The three most common forms of impact printers are:
    • Dot-matrix.
    • Daisy-wheel.
    • Line printers.

Key Points

• Dot-matrix Printers 
  • The technology behind dot-matrix printing is in such a way that the paper is pressed against a drum (a rubber-coated cylinder).
  • The electromagnetically-driven printhead moves across the paper and strikes the printer ribbon situated between the paper and printhead pin.
  • The impact of the printhead against the printer ribbon imprints ink dots on the paper which create human-readable characters.

Additional Information

• Laser Printer
  • ​A laser printer is a printer that uses a focused beam of light to transfer text and images onto paper. 
• Inkjet printer
  • ​Inkjet printers, as the name implies, use ink to print text, graphics, and images onto various types of paper. 
  • Inkjet printers, cartridges, and supplies are more widely available therefore cheaper than their thermal printer.
• Thermal printer​
  • Thermal printers use tiny heating elements to activate or transfer pigments.
  • Thermal printers are used most commonly to create labels, safety signs.

The correct answer is Flash memory.

Key Points

• Flash memory is a type of memory that functions similarly to RAM and ROM.
• You can write data to flash memory just like you can to RAM, however, unlike ROM, the data isn't lost when the power is turned off. Read-only memory is referred to as ROM.
• Although the CPU can read from ROM, it cannot write to or modify it. ROM is a long-term storage medium.
• Random-access memory (RAM) refers to memory that the microprocessor can read from and write to. It's done in RAM when you construct something in memory.

Important Points

• The smallest and fastest memory in a computer is register memory.
• External memory, often known as secondary memory, refers to the numerous storage media that a computer might use to store data and applications.
• Cache memory, often known as cache, is a supplementary memory system that saves frequently used instructions and data in order for the central processing unit (CPU) of a computer to perform them more quickly.